21640679485 has 8 divisors (see below), whose sum is σ = 26806519296. Its totient is φ = 16754074320.

The previous prime is 21640679479. The next prime is 21640679497. The reversal of 21640679485 is 58497604612.

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

It is not a de Polignac number, because 21640679485 - 2⁹ = 21640678973 is a prime.

It is a Duffinian number.

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, 69808489 + ... + 69808798.

It is an arithmetic number, because the mean of its divisors is an integer number (3350814912).

Almost surely, 2^21640679485 is an apocalyptic number.

It is an amenable number.

21640679485 is a deficient number, since it is larger than the sum of its proper divisors (5165839811).

21640679485 is a wasteful number, since it uses less digits than its factorization.

21640679485 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139617323.

The product of its (nonzero) digits is 2903040, while the sum is 52.

The spelling of 21640679485 in words is "twenty-one billion, six hundred forty million, six hundred seventy-nine thousand, four hundred eighty-five".