21570889 has 8 divisors (see below), whose sum is σ = 22292928. Its totient is φ = 20856240.

The previous prime is 21570863. The next prime is 21570917. The reversal of 21570889 is 98807512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21570889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21570839) 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, 4434 + ... + 7924.

It is an arithmetic number, because the mean of its divisors is an integer number (2786616).

Almost surely, 2^21570889 is an apocalyptic number.

It is an amenable number.

21570889 is a deficient number, since it is larger than the sum of its proper divisors (722039).

21570889 is a wasteful number, since it uses less digits than its factorization.

21570889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3695.

The product of its (nonzero) digits is 40320, while the sum is 40.

The square root of 21570889 is about 4644.4471145660. The cubic root of 21570889 is about 278.3701614608.

The spelling of 21570889 in words is "twenty-one million, five hundred seventy thousand, eight hundred eighty-nine".