400642537 has 2 divisors, whose sum is σ = 400642538. Its totient is φ = 400642536.

The previous prime is 400642399. The next prime is 400642547. The reversal of 400642537 is 735246004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 395850816 + 4791721 = 19896^2 + 2189^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-400642537 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 400642499 and 400642508.

It is not a weakly prime, because it can be changed into another prime (400642547) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200321268 + 200321269.

It is an arithmetic number, because the mean of its divisors is an integer number (200321269).

Almost surely, 2^400642537 is an apocalyptic number.

It is an amenable number.

400642537 is a deficient number, since it is larger than the sum of its proper divisors (1).

400642537 is an equidigital number, since it uses as much as digits as its factorization.

400642537 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20160, while the sum is 31.

The square root of 400642537 is about 20016.0569793354. The cubic root of 400642537 is about 737.2006097622.

The spelling of 400642537 in words is "four hundred million, six hundred forty-two thousand, five hundred thirty-seven".