21713646 has 16 divisors (see below), whose sum is σ = 44039808. Its totient is φ = 7135800.

The previous prime is 21713639. The next prime is 21713669. The reversal of 21713646 is 64631712.

It is a super-2 number, since 2×21713646² = 942964845226632, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25060 + ... + 25911.

It is an arithmetic number, because the mean of its divisors is an integer number (2752488).

Almost surely, 2^21713646 is an apocalyptic number.

21713646 is an abundant number, since it is smaller than the sum of its proper divisors (22326162).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21713646 is a wasteful number, since it uses less digits than its factorization.

21713646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51047.

The product of its digits is 6048, while the sum is 30.

The square root of 21713646 is about 4659.7903386311. The cubic root of 21713646 is about 278.9828999938.

The spelling of 21713646 in words is "twenty-one million, seven hundred thirteen thousand, six hundred forty-six".