21369907 has 4 divisors (see below), whose sum is σ = 23013760. Its totient is φ = 19726056.

The previous prime is 21369893. The next prime is 21369911. The reversal of 21369907 is 70996312.

21369907 is nontrivially palindromic in base 12.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21369907 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21369917) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 821907 + ... + 821932.

It is an arithmetic number, because the mean of its divisors is an integer number (5753440).

Almost surely, 2^21369907 is an apocalyptic number.

21369907 is a deficient number, since it is larger than the sum of its proper divisors (1643853).

21369907 is a wasteful number, since it uses less digits than its factorization.

21369907 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1643852.

The product of its (nonzero) digits is 20412, while the sum is 37.

The square root of 21369907 is about 4622.7596736149. The cubic root of 21369907 is about 277.5029115297.

The spelling of 21369907 in words is "twenty-one million, three hundred sixty-nine thousand, nine hundred seven".