400537861 has 2 divisors, whose sum is σ = 400537862. Its totient is φ = 400537860.

The previous prime is 400537853. The next prime is 400537889. The reversal of 400537861 is 168735004.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 212984836 + 187553025 = 14594^2 + 13695^2 .

It is a cyclic number.

It is not a de Polignac number, because 400537861 - 2³ = 400537853 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400537061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200268930 + 200268931.

It is an arithmetic number, because the mean of its divisors is an integer number (200268931).

Almost surely, 2^400537861 is an apocalyptic number.

It is an amenable number.

400537861 is a deficient number, since it is larger than the sum of its proper divisors (1).

400537861 is an equidigital number, since it uses as much as digits as its factorization.

400537861 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 34.

The square root of 400537861 is about 20013.4420078107. The cubic root of 400537861 is about 737.1364012926.

The spelling of 400537861 in words is "four hundred million, five hundred thirty-seven thousand, eight hundred sixty-one".