21156914 has 4 divisors (see below), whose sum is σ = 31735374. Its totient is φ = 10578456.

The previous prime is 21156913. The next prime is 21156923. The reversal of 21156914 is 41965112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 21022225 + 134689 = 4585^2 + 367^2 .

It is not an unprimeable number, because it can be changed into a prime (21156913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5289227 + ... + 5289230.

Almost surely, 2^21156914 is an apocalyptic number.

21156914 is a deficient number, since it is larger than the sum of its proper divisors (10578460).

21156914 is a wasteful number, since it uses less digits than its factorization.

21156914 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10578459.

The product of its digits is 2160, while the sum is 29.

The square root of 21156914 is about 4599.6645529864. The cubic root of 21156914 is about 276.5778779941.

The spelling of 21156914 in words is "twenty-one million, one hundred fifty-six thousand, nine hundred fourteen".