21297160 has 32 divisors (see below), whose sum is σ = 48600000. Its totient is φ = 8397760.

The previous prime is 21297151. The next prime is 21297161. The reversal of 21297160 is 6179212.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21297161) 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, 910 + ... + 6589.

It is an arithmetic number, because the mean of its divisors is an integer number (1518750).

Almost surely, 2^21297160 is an apocalyptic number.

21297160 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21297160 is an abundant number, since it is smaller than the sum of its proper divisors (27302840).

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

21297160 is a wasteful number, since it uses less digits than its factorization.

21297160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7581 (or 7577 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 28.

The square root of 21297160 is about 4614.8846139422. The cubic root of 21297160 is about 277.1876636280.

The spelling of 21297160 in words is "twenty-one million, two hundred ninety-seven thousand, one hundred sixty".