2157664727 has 2 divisors, whose sum is σ = 2157664728. Its totient is φ = 2157664726.

The previous prime is 2157664627. The next prime is 2157664783. The reversal of 2157664727 is 7274667512.

2157664727 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2157664727 - 2²⁸ = 1889229271 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2157664787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1078832363 + 1078832364.

It is an arithmetic number, because the mean of its divisors is an integer number (1078832364).

Almost surely, 2^2157664727 is an apocalyptic number.

2157664727 is a deficient number, since it is larger than the sum of its proper divisors (1).

2157664727 is an equidigital number, since it uses as much as digits as its factorization.

2157664727 is an evil number, because the sum of its binary digits is even.

The product of its digits is 987840, while the sum is 47.

The square root of 2157664727 is about 46450.6698229423. The cubic root of 2157664727 is about 1292.1947948153.

The spelling of 2157664727 in words is "two billion, one hundred fifty-seven million, six hundred sixty-four thousand, seven hundred twenty-seven".