21156106 has 8 divisors (see below), whose sum is σ = 31773924. Its totient is φ = 10564800.

The previous prime is 21156077. The next prime is 21156127. The reversal of 21156106 is 60165112.

It can be written as a sum of positive squares in 2 ways, for example, as 18879025 + 2277081 = 4345^2 + 1509^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4495 + ... + 7906.

Almost surely, 2^21156106 is an apocalyptic number.

21156106 is a deficient number, since it is larger than the sum of its proper divisors (10617818).

21156106 is a wasteful number, since it uses less digits than its factorization.

21156106 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13256.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 21156106 is about 4599.5767196558. The cubic root of 21156106 is about 276.5743570368.

The spelling of 21156106 in words is "twenty-one million, one hundred fifty-six thousand, one hundred six".