399183887 has 4 divisors (see below), whose sum is σ = 402097776. Its totient is φ = 396270000.

The previous prime is 399183881. The next prime is 399183907. The reversal of 399183887 is 788381993.

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 399183887 - 2²² = 394989583 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 (399183881) 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, 1456739 + ... + 1457012.

It is an arithmetic number, because the mean of its divisors is an integer number (100524444).

Almost surely, 2^399183887 is an apocalyptic number.

399183887 is a deficient number, since it is larger than the sum of its proper divisors (2913889).

399183887 is a wasteful number, since it uses less digits than its factorization.

399183887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2913888.

The product of its digits is 2612736, while the sum is 56.

The square root of 399183887 is about 19979.5867574883. The cubic root of 399183887 is about 736.3048608813.

It can be divided in two parts, 3991 and 83887, that added together give a palindrome (87878).

The spelling of 399183887 in words is "three hundred ninety-nine million, one hundred eighty-three thousand, eight hundred eighty-seven".