21587097 has 48 divisors (see below), whose sum is σ = 36115200. Its totient is φ = 11400480.

The previous prime is 21587089. The next prime is 21587101. The reversal of 21587097 is 79078512.

It is not a de Polignac number, because 21587097 - 2³ = 21587089 is a prime.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21587017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 164722 + ... + 164852.

It is an arithmetic number, because the mean of its divisors is an integer number (752400).

Almost surely, 2^21587097 is an apocalyptic number.

It is an amenable number.

21587097 is a deficient number, since it is larger than the sum of its proper divisors (14528103).

21587097 is a wasteful number, since it uses less digits than its factorization.

21587097 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 226 (or 219 counting only the distinct ones).

The product of its (nonzero) digits is 35280, while the sum is 39.

The square root of 21587097 is about 4646.1916663005. The cubic root of 21587097 is about 278.4398648778.

The spelling of 21587097 in words is "twenty-one million, five hundred eighty-seven thousand, ninety-seven".