399666383 has 4 divisors (see below), whose sum is σ = 402118488. Its totient is φ = 397214280.

The previous prime is 399666373. The next prime is 399666389. The reversal of 399666383 is 383666993.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 383666993 = 137 ⋅2800489.

It is a cyclic number.

It is not a de Polignac number, because 399666383 - 2²² = 395472079 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 (399666389) 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, 1225808 + ... + 1226133.

It is an arithmetic number, because the mean of its divisors is an integer number (100529622).

Almost surely, 2^399666383 is an apocalyptic number.

399666383 is a deficient number, since it is larger than the sum of its proper divisors (2452105).

399666383 is a wasteful number, since it uses less digits than its factorization.

399666383 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2452104.

The product of its digits is 3779136, while the sum is 53.

The square root of 399666383 is about 19991.6578352072. The cubic root of 399666383 is about 736.6014001631.

The spelling of 399666383 in words is "three hundred ninety-nine million, six hundred sixty-six thousand, three hundred eighty-three".