399406877 has 2 divisors, whose sum is σ = 399406878. Its totient is φ = 399406876.

The previous prime is 399406859. The next prime is 399406921. The reversal of 399406877 is 778604993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 355661881 + 43744996 = 18859^2 + 6614^2 .

It is a cyclic number.

It is not a de Polignac number, because 399406877 - 2²⁴ = 382629661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399606877) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199703438 + 199703439.

It is an arithmetic number, because the mean of its divisors is an integer number (199703439).

Almost surely, 2^399406877 is an apocalyptic number.

It is an amenable number.

399406877 is a deficient number, since it is larger than the sum of its proper divisors (1).

399406877 is an equidigital number, since it uses as much as digits as its factorization.

399406877 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2286144, while the sum is 53.

The square root of 399406877 is about 19985.1664241257. The cubic root of 399406877 is about 736.4419389406.

The spelling of 399406877 in words is "three hundred ninety-nine million, four hundred six thousand, eight hundred seventy-seven".