2157557 has 2 divisors, whose sum is σ = 2157558. Its totient is φ = 2157556.

The previous prime is 2157539. The next prime is 2157559. The reversal of 2157557 is 7557512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1503076 + 654481 = 1226^2 + 809^2 .

It is a cyclic number.

It is not a de Polignac number, because 2157557 - 2⁸ = 2157301 is a prime.

Together with 2157559, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p₁₅₉₇₈₂ and since 2157557 and 159782 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2157559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1078778 + 1078779.

It is an arithmetic number, because the mean of its divisors is an integer number (1078779).

2^2157557 is an apocalyptic number.

It is an amenable number.

2157557 is a deficient number, since it is larger than the sum of its proper divisors (1).

2157557 is an equidigital number, since it uses as much as digits as its factorization.

2157557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12250, while the sum is 32.

The square root of 2157557 is about 1468.8624850543. The cubic root of 2157557 is about 129.2173289067.

The spelling of 2157557 in words is "two million, one hundred fifty-seven thousand, five hundred fifty-seven".