21156107 has 8 divisors (see below), whose sum is σ = 24364032. Its totient is φ = 17994600.

The previous prime is 21156077. The next prime is 21156127. The reversal of 21156107 is 70165112.

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

It is a cyclic number.

It is not a de Polignac number, because 21156107 - 2¹² = 21152011 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21156127) 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, 10619 + ... + 12452.

It is an arithmetic number, because the mean of its divisors is an integer number (3045504).

Almost surely, 2^21156107 is an apocalyptic number.

21156107 is a deficient number, since it is larger than the sum of its proper divisors (3207925).

21156107 is a wasteful number, since it uses less digits than its factorization.

21156107 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23209.

The product of its (nonzero) digits is 420, while the sum is 23.

The square root of 21156107 is about 4599.5768283615. The cubic root of 21156107 is about 276.5743613945.

The spelling of 21156107 in words is "twenty-one million, one hundred fifty-six thousand, one hundred seven".