399101993 has 4 divisors (see below), whose sum is σ = 399147648. Its totient is φ = 399056340.

The previous prime is 399101987. The next prime is 399102001.

399101993 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 399101993 - 2⁸ = 399101737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399107993) 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, 5153 + ... + 28718.

It is an arithmetic number, because the mean of its divisors is an integer number (99786912).

Almost surely, 2^399101993 is an apocalyptic number.

It is an amenable number.

399101993 is a deficient number, since it is larger than the sum of its proper divisors (45655).

399101993 is a wasteful number, since it uses less digits than its factorization.

399101993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45654.

The product of its (nonzero) digits is 59049, while the sum is 44.

The square root of 399101993 is about 19977.5372105773. The cubic root of 399101993 is about 736.2545055803.

The spelling of 399101993 in words is "three hundred ninety-nine million, one hundred one thousand, nine hundred ninety-three".