399880837 has 2 divisors, whose sum is σ = 399880838. Its totient is φ = 399880836.

The previous prime is 399880823. The next prime is 399880849. The reversal of 399880837 is 738088993.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 398162116 + 1718721 = 19954^2 + 1311^2 .

It is a cyclic number.

It is not a de Polignac number, because 399880837 - 2¹⁹ = 399356549 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399880807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199940418 + 199940419.

It is an arithmetic number, because the mean of its divisors is an integer number (199940419).

Almost surely, 2^399880837 is an apocalyptic number.

It is an amenable number.

399880837 is a deficient number, since it is larger than the sum of its proper divisors (1).

399880837 is an equidigital number, since it uses as much as digits as its factorization.

399880837 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2612736, while the sum is 55.

The square root of 399880837 is about 19997.0207030947. The cubic root of 399880837 is about 736.7331257537.

The spelling of 399880837 in words is "three hundred ninety-nine million, eight hundred eighty thousand, eight hundred thirty-seven".