399571947 has 24 divisors (see below), whose sum is σ = 619185840. Its totient is φ = 257191200.

The previous prime is 399571943. The next prime is 399571951. The reversal of 399571947 is 749175993.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (399571943) and next prime (399571951).

It is not a de Polignac number, because 399571947 - 2² = 399571943 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 399571893 and 399571902.

It is not an unprimeable number, because it can be changed into a prime (399571943) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21304 + ... + 35397.

It is an arithmetic number, because the mean of its divisors is an integer number (25799410).

Almost surely, 2^399571947 is an apocalyptic number.

399571947 is a deficient number, since it is larger than the sum of its proper divisors (219613893).

399571947 is an equidigital number, since it uses as much as digits as its factorization.

399571947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56745 (or 56733 counting only the distinct ones).

The product of its digits is 2143260, while the sum is 54.

The square root of 399571947 is about 19989.2958105082. The cubic root of 399571947 is about 736.5433791300.

The spelling of 399571947 in words is "three hundred ninety-nine million, five hundred seventy-one thousand, nine hundred forty-seven".