399278479 has 4 divisors (see below), whose sum is σ = 400255120. Its totient is φ = 398301840.

The previous prime is 399278449. The next prime is 399278491. The reversal of 399278479 is 974872993.

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 399278479 - 2²⁷ = 265060751 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 (399278449) 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, 487707 + ... + 488524.

It is an arithmetic number, because the mean of its divisors is an integer number (100063780).

Almost surely, 2^399278479 is an apocalyptic number.

399278479 is a deficient number, since it is larger than the sum of its proper divisors (976641).

399278479 is an equidigital number, since it uses as much as digits as its factorization.

399278479 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 976640.

The product of its digits is 6858432, while the sum is 58.

The square root of 399278479 is about 19981.9538333968. The cubic root of 399278479 is about 736.3630154069.

The spelling of 399278479 in words is "three hundred ninety-nine million, two hundred seventy-eight thousand, four hundred seventy-nine".