61722240 has 256 divisors, whose sum is σ = 218557440. Its totient is φ = 14745600.

The previous prime is 61722187. The next prime is 61722251. The reversal of 61722240 is 4222716.

61722240 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 61722240.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1011810 + ... + 1011870.

It is an arithmetic number, because the mean of its divisors is an integer number (853740).

Almost surely, 2^61722240 is an apocalyptic number.

61722240 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61722240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109278720).

61722240 is an abundant number, since it is smaller than the sum of its proper divisors (156835200).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61722240 is a wasteful number, since it uses less digits than its factorization.

61722240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131 (or 119 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 24.

The square root of 61722240 is about 7856.3502976891. The cubic root of 61722240 is about 395.1972309902.

Adding to 61722240 its reverse (4222716), we get a palindrome (65944956).

The spelling of 61722240 in words is "sixty-one million, seven hundred twenty-two thousand, two hundred forty".