21677257947 has 16 divisors (see below), whose sum is σ = 30840997760. Its totient is φ = 13503350592.

The previous prime is 21677257919. The next prime is 21677257961. The reversal of 21677257947 is 74975277612.

It is not a de Polignac number, because 21677257947 - 2⁶ = 21677257883 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21677257907) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2600653 + ... + 2608974.

It is an arithmetic number, because the mean of its divisors is an integer number (1927562360).

Almost surely, 2^21677257947 is an apocalyptic number.

21677257947 is a deficient number, since it is larger than the sum of its proper divisors (9163739813).

21677257947 is a wasteful number, since it uses less digits than its factorization.

21677257947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5209722.

The product of its digits is 10372320, while the sum is 57.

The spelling of 21677257947 in words is "twenty-one billion, six hundred seventy-seven million, two hundred fifty-seven thousand, nine hundred forty-seven".