21069257979 has 48 divisors (see below), whose sum is σ = 35816555264. Its totient is φ = 10781622720.

The previous prime is 21069257959. The next prime is 21069257999. The reversal of 21069257979 is 97975296012.

It is an interprime number because it is at equal distance from previous prime (21069257959) and next prime (21069257999).

It is not a de Polignac number, because 21069257979 - 2⁸ = 21069257723 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21069257959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 108369 + ... + 232125.

Almost surely, 2^21069257979 is an apocalyptic number.

21069257979 is a deficient number, since it is larger than the sum of its proper divisors (14747297285).

21069257979 is a wasteful number, since it uses less digits than its factorization.

21069257979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123856 (or 123845 counting only the distinct ones).

The product of its (nonzero) digits is 4286520, while the sum is 57.

The spelling of 21069257979 in words is "twenty-one billion, sixty-nine million, two hundred fifty-seven thousand, nine hundred seventy-nine".