399342409291 has 4 divisors (see below), whose sum is σ = 456391324912. Its totient is φ = 342293493672.

The previous prime is 399342409223. The next prime is 399342409321. The reversal of 399342409291 is 192904243993.

It is a happy number.

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 399342409291 - 2⁷ = 399342409163 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399342409891) 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, 28524457800 + ... + 28524457813.

It is an arithmetic number, because the mean of its divisors is an integer number (114097831228).

Almost surely, 2^399342409291 is an apocalyptic number.

399342409291 is a deficient number, since it is larger than the sum of its proper divisors (57048915621).

399342409291 is an equidigital number, since it uses as much as digits as its factorization.

399342409291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57048915620.

The product of its (nonzero) digits is 3779136, while the sum is 55.

It can be divided in two parts, 39934 and 2409291, that added together give a square (2449225 = 1565²).

The spelling of 399342409291 in words is "three hundred ninety-nine billion, three hundred forty-two million, four hundred nine thousand, two hundred ninety-one".