400400043977 has 2 divisors, whose sum is σ = 400400043978. Its totient is φ = 400400043976.

The previous prime is 400400043941. The next prime is 400400044021. The reversal of 400400043977 is 779340004004.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 367695491641 + 32704552336 = 606379^2 + 180844^2 .

It is a cyclic number.

It is not a de Polignac number, because 400400043977 - 2¹² = 400400039881 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 400400043977.

It is not a weakly prime, because it can be changed into another prime (400400043677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200200021988 + 200200021989.

It is an arithmetic number, because the mean of its divisors is an integer number (200200021989).

Almost surely, 2^400400043977 is an apocalyptic number.

It is an amenable number.

400400043977 is a deficient number, since it is larger than the sum of its proper divisors (1).

400400043977 is an equidigital number, since it uses as much as digits as its factorization.

400400043977 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 84672, while the sum is 38.

The spelling of 400400043977 in words is "four hundred billion, four hundred million, forty-three thousand, nine hundred seventy-seven".