657071081 has 2 divisors, whose sum is σ = 657071082. Its totient is φ = 657071080.

The previous prime is 657071059. The next prime is 657071083. The reversal of 657071081 is 180170756.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 452838400 + 204232681 = 21280^2 + 14291^2 .

It is a cyclic number.

It is not a de Polignac number, because 657071081 - 2⁶ = 657071017 is a prime.

It is a super-2 number, since 2×657071081² = 863484810973017122, which contains 22 as substring.

Together with 657071083, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (657071083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328535540 + 328535541.

It is an arithmetic number, because the mean of its divisors is an integer number (328535541).

Almost surely, 2^657071081 is an apocalyptic number.

It is an amenable number.

657071081 is a deficient number, since it is larger than the sum of its proper divisors (1).

657071081 is an equidigital number, since it uses as much as digits as its factorization.

657071081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11760, while the sum is 35.

The square root of 657071081 is about 25633.3977654153. The cubic root of 657071081 is about 869.3689354995.

The spelling of 657071081 in words is "six hundred fifty-seven million, seventy-one thousand, eighty-one".