21692051 has 12 divisors (see below), whose sum is σ = 23548128. Its totient is φ = 19969152.

The previous prime is 21691979. The next prime is 21692063. The reversal of 21692051 is 15029612.

It is a de Polignac number, because none of the positive numbers 2^k-21692051 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21692051.

It is not an unprimeable number, because it can be changed into a prime (21692071) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12785 + ... + 14381.

It is an arithmetic number, because the mean of its divisors is an integer number (1962344).

Almost surely, 2^21692051 is an apocalyptic number.

21692051 is a deficient number, since it is larger than the sum of its proper divisors (1856077).

21692051 is a wasteful number, since it uses less digits than its factorization.

21692051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1678 (or 1661 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 21692051 is about 4657.4725978797. The cubic root of 21692051 is about 278.8903831488.

The spelling of 21692051 in words is "twenty-one million, six hundred ninety-two thousand, fifty-one".