399478231 has 4 divisors (see below), whose sum is σ = 399537864. Its totient is φ = 399418600.

The previous prime is 399478229. The next prime is 399478241. The reversal of 399478231 is 132874993.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 399478231 - 2¹ = 399478229 is a prime.

It is a super-2 number, since 2×399478231² = 319165714085778722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399478241) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18280 + ... + 33661.

It is an arithmetic number, because the mean of its divisors is an integer number (99884466).

Almost surely, 2^399478231 is an apocalyptic number.

399478231 is a deficient number, since it is larger than the sum of its proper divisors (59633).

399478231 is an equidigital number, since it uses as much as digits as its factorization.

399478231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59632.

The product of its digits is 326592, while the sum is 46.

The square root of 399478231 is about 19986.9515184282. The cubic root of 399478231 is about 736.4857914231.

The spelling of 399478231 in words is "three hundred ninety-nine million, four hundred seventy-eight thousand, two hundred thirty-one".