399931907761 has 2 divisors, whose sum is σ = 399931907762. Its totient is φ = 399931907760.

The previous prime is 399931907747. The next prime is 399931907783. The reversal of 399931907761 is 167709139993.

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., 381746036736 + 18185871025 = 617856^2 + 134855^2 .

It is a cyclic number.

It is not a de Polignac number, because 399931907761 - 2¹¹ = 399931905713 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 399931907693 and 399931907702.

It is not a weakly prime, because it can be changed into another prime (399931907261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199965953880 + 199965953881.

It is an arithmetic number, because the mean of its divisors is an integer number (199965953881).

Almost surely, 2^399931907761 is an apocalyptic number.

It is an amenable number.

399931907761 is a deficient number, since it is larger than the sum of its proper divisors (1).

399931907761 is an equidigital number, since it uses as much as digits as its factorization.

399931907761 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17360406, while the sum is 64.

The spelling of 399931907761 in words is "three hundred ninety-nine billion, nine hundred thirty-one million, nine hundred seven thousand, seven hundred sixty-one".