399133021 has 8 divisors (see below), whose sum is σ = 482984640. Its totient is φ = 321989568.

The previous prime is 399133013. The next prime is 399133051. The reversal of 399133021 is 120331993.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 399133021 - 2³ = 399133013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399133051) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1676911 + ... + 1677148.

It is an arithmetic number, because the mean of its divisors is an integer number (60373080).

Almost surely, 2^399133021 is an apocalyptic number.

It is an amenable number.

399133021 is a deficient number, since it is larger than the sum of its proper divisors (83851619).

399133021 is a wasteful number, since it uses less digits than its factorization.

399133021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3354083.

The product of its (nonzero) digits is 4374, while the sum is 31.

The square root of 399133021 is about 19978.3137676832. The cubic root of 399133021 is about 736.2735850080.

The spelling of 399133021 in words is "three hundred ninety-nine million, one hundred thirty-three thousand, twenty-one".