21617612 has 6 divisors (see below), whose sum is σ = 37830828. Its totient is φ = 10808804.

The previous prime is 21617581. The next prime is 21617621. The reversal of 21617612 is 21671612.

It is a super-2 number, since 2×21617612² = 934642297165088, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2702198 + ... + 2702205.

It is an arithmetic number, because the mean of its divisors is an integer number (6305138).

Almost surely, 2^21617612 is an apocalyptic number.

It is an amenable number.

21617612 is a deficient number, since it is larger than the sum of its proper divisors (16213216).

21617612 is a wasteful number, since it uses less digits than its factorization.

21617612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5404407 (or 5404405 counting only the distinct ones).

The product of its digits is 1008, while the sum is 26.

The square root of 21617612 is about 4649.4743788949. The cubic root of 21617612 is about 278.5710017338.

The spelling of 21617612 in words is "twenty-one million, six hundred seventeen thousand, six hundred twelve".