21712715 has 8 divisors (see below), whose sum is σ = 26093760. Its totient is φ = 17344512.

The previous prime is 21712697. The next prime is 21712729. The reversal of 21712715 is 51721712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21712715 - 2⁶ = 21712651 is a prime.

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, 1022 + ... + 6668.

It is an arithmetic number, because the mean of its divisors is an integer number (3261720).

Almost surely, 2^21712715 is an apocalyptic number.

21712715 is a deficient number, since it is larger than the sum of its proper divisors (4381045).

21712715 is an equidigital number, since it uses as much as digits as its factorization.

21712715 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6421.

The product of its digits is 980, while the sum is 26.

The square root of 21712715 is about 4659.6904403619. The cubic root of 21712715 is about 278.9789126888.

The spelling of 21712715 in words is "twenty-one million, seven hundred twelve thousand, seven hundred fifteen".