21713679 has 24 divisors (see below), whose sum is σ = 35249760. Its totient is φ = 12779712.

The previous prime is 21713677. The next prime is 21713683. The reversal of 21713679 is 97631712.

It is a happy number.

It is not a de Polignac number, because 21713679 - 2¹ = 21713677 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21713677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1344 + ... + 6725.

It is an arithmetic number, because the mean of its divisors is an integer number (1468740).

Almost surely, 2^21713679 is an apocalyptic number.

21713679 is a deficient number, since it is larger than the sum of its proper divisors (13536081).

21713679 is a wasteful number, since it uses less digits than its factorization.

21713679 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8111 (or 8108 counting only the distinct ones).

The product of its digits is 15876, while the sum is 36.

The square root of 21713679 is about 4659.7938795616. The cubic root of 21713679 is about 278.9830413248.

The spelling of 21713679 in words is "twenty-one million, seven hundred thirteen thousand, six hundred seventy-nine".