221621460 has 24 divisors (see below), whose sum is σ = 620540256. Its totient is φ = 59099040.

The previous prime is 221621437. The next prime is 221621467. The reversal of 221621460 is 64126122.

It is a self number, because there is not a number n which added to its sum of digits gives 221621460.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221621467) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1846786 + ... + 1846905.

It is an arithmetic number, because the mean of its divisors is an integer number (25855844).

Almost surely, 2^221621460 is an apocalyptic number.

221621460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221621460 is an abundant number, since it is smaller than the sum of its proper divisors (398918796).

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

221621460 is a wasteful number, since it uses less digits than its factorization.

221621460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3693703 (or 3693701 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 221621460 is about 14886.9560354023. The cubic root of 221621460 is about 605.1605429647.

Adding to 221621460 its reverse (64126122), we get a palindrome (285747582).

The spelling of 221621460 in words is "two hundred twenty-one million, six hundred twenty-one thousand, four hundred sixty".