400657 has 2 divisors, whose sum is σ = 400658. Its totient is φ = 400656.

The previous prime is 400651. The next prime is 400679. The reversal of 400657 is 756004.

It is an a-pointer prime, because the next prime (400679) can be obtained adding 400657 to its sum of digits (22).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 207936 + 192721 = 456^2 + 439^2 .

It is a cyclic number.

It is not a de Polignac number, because 400657 - 2¹¹ = 398609 is a prime.

It is not a weakly prime, because it can be changed into another prime (400651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200328 + 200329.

It is an arithmetic number, because the mean of its divisors is an integer number (200329).

2⁴⁰⁰⁶⁵⁷ is an apocalyptic number.

It is an amenable number.

400657 is a deficient number, since it is larger than the sum of its proper divisors (1).

400657 is an equidigital number, since it uses as much as digits as its factorization.

400657 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 840, while the sum is 22.

The square root of 400657 is about 632.9747230340. The cubic root of 400657 is about 73.7209480516.

The spelling of 400657 in words is "four hundred thousand, six hundred fifty-seven".