21727377647 has 2 divisors, whose sum is σ = 21727377648. Its totient is φ = 21727377646.

The previous prime is 21727377611. The next prime is 21727377803. The reversal of 21727377647 is 74677372712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21727377647 - 2³⁴ = 4547508463 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21727377047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10863688823 + 10863688824.

It is an arithmetic number, because the mean of its divisors is an integer number (10863688824).

Almost surely, 2^21727377647 is an apocalyptic number.

21727377647 is a deficient number, since it is larger than the sum of its proper divisors (1).

21727377647 is an equidigital number, since it uses as much as digits as its factorization.

21727377647 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4840416, while the sum is 53.

The spelling of 21727377647 in words is "twenty-one billion, seven hundred twenty-seven million, three hundred seventy-seven thousand, six hundred forty-seven".