21005692 has 6 divisors (see below), whose sum is σ = 36759968. Its totient is φ = 10502844.

The previous prime is 21005689. The next prime is 21005701. The reversal of 21005692 is 29650012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2625708 + ... + 2625715.

Almost surely, 2^21005692 is an apocalyptic number.

It is an amenable number.

21005692 is a deficient number, since it is larger than the sum of its proper divisors (15754276).

21005692 is a wasteful number, since it uses less digits than its factorization.

21005692 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5251427 (or 5251425 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 21005692 is about 4583.1967009938. The cubic root of 21005692 is about 275.9173420473.

The spelling of 21005692 in words is "twenty-one million, five thousand, six hundred ninety-two".