21764012 has 36 divisors (see below), whose sum is σ = 41209224. Its totient is φ = 10053120.

The previous prime is 21763999. The next prime is 21764021. The reversal of 21764012 is 21046712.

It is a super-2 number, since 2×21764012² = 947344436672288, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 77312 + ... + 77592.

Almost surely, 2^21764012 is an apocalyptic number.

It is an amenable number.

21764012 is a deficient number, since it is larger than the sum of its proper divisors (19445212).

21764012 is a wasteful number, since it uses less digits than its factorization.

21764012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 386 (or 367 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 21764012 is about 4665.1915287585. The cubic root of 21764012 is about 279.1984388382.

The spelling of 21764012 in words is "twenty-one million, seven hundred sixty-four thousand, twelve".