64251720 has 96 divisors (see below), whose sum is σ = 224897400. Its totient is φ = 15814656.

The previous prime is 64251683. The next prime is 64251743. The reversal of 64251720 is 2715246.

64251720 is a `hidden beast` number, since 642 + 5 + 17 + 2 + 0 = 666.

64251720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 35928036 + 28323684 = 5994^2 + 5322^2 .

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 23 ways as a sum of consecutive naturals, for example, 2185 + ... + 11544.

Almost surely, 2^64251720 is an apocalyptic number.

64251720 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 64251720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112448700).

64251720 is an abundant number, since it is smaller than the sum of its proper divisors (160645680).

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

64251720 is a wasteful number, since it uses less digits than its factorization.

64251720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13759 (or 13752 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 64251720 is about 8015.7170608748. The cubic root of 64251720 is about 400.5237306329.

Adding to 64251720 its reverse (2715246), we get a palindrome (66966966).

The spelling of 64251720 in words is "sixty-four million, two hundred fifty-one thousand, seven hundred twenty".