21716588 has 6 divisors (see below), whose sum is σ = 38004036. Its totient is φ = 10858292.

The previous prime is 21716587. The next prime is 21716603. The reversal of 21716588 is 88561712.

It is a super-2 number, since 2×21716588² = 943220388723488, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21716587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2714570 + ... + 2714577.

It is an arithmetic number, because the mean of its divisors is an integer number (6334006).

Almost surely, 2^21716588 is an apocalyptic number.

It is an amenable number.

21716588 is a deficient number, since it is larger than the sum of its proper divisors (16287448).

21716588 is a wasteful number, since it uses less digits than its factorization.

21716588 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5429151 (or 5429149 counting only the distinct ones).

The product of its digits is 26880, while the sum is 38.

The square root of 21716588 is about 4660.1060073779. The cubic root of 21716588 is about 278.9954993000.

The spelling of 21716588 in words is "twenty-one million, seven hundred sixteen thousand, five hundred eighty-eight".