399581071 has 2 divisors, whose sum is σ = 399581072. Its totient is φ = 399581070.

The previous prime is 399581033. The next prime is 399581081. The reversal of 399581071 is 170185993.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 399581071 - 2⁷ = 399580943 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399581011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199790535 + 199790536.

It is an arithmetic number, because the mean of its divisors is an integer number (199790536).

Almost surely, 2^399581071 is an apocalyptic number.

399581071 is a deficient number, since it is larger than the sum of its proper divisors (1).

399581071 is an equidigital number, since it uses as much as digits as its factorization.

399581071 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 68040, while the sum is 43.

The square root of 399581071 is about 19989.5240313520. The cubic root of 399581071 is about 736.5489852715.

The spelling of 399581071 in words is "three hundred ninety-nine million, five hundred eighty-one thousand, seventy-one".