21097087 has 8 divisors (see below), whose sum is σ = 24226560. Its totient is φ = 18169560.

The previous prime is 21097057. The next prime is 21097091. The reversal of 21097087 is 78079012.

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-21097087 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21097057) 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, 50263 + ... + 50680.

It is an arithmetic number, because the mean of its divisors is an integer number (3028320).

Almost surely, 2^21097087 is an apocalyptic number.

21097087 is a deficient number, since it is larger than the sum of its proper divisors (3129473).

21097087 is a wasteful number, since it uses less digits than its factorization.

21097087 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100973.

The product of its (nonzero) digits is 7056, while the sum is 34.

The square root of 21097087 is about 4593.1565398972. The cubic root of 21097087 is about 276.3169318379.

The spelling of 21097087 in words is "twenty-one million, ninety-seven thousand, eighty-seven".