399976813 has 2 divisors, whose sum is σ = 399976814. Its totient is φ = 399976812.

The previous prime is 399976747. The next prime is 399976879. The reversal of 399976813 is 318679993.

It is a balanced prime because it is at equal distance from previous prime (399976747) and next prime (399976879).

It can be written as a sum of positive squares in only one way, i.e., 288082729 + 111894084 = 16973^2 + 10578^2 .

It is a cyclic number.

It is not a de Polignac number, because 399976813 - 2⁹ = 399976301 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399977813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199988406 + 199988407.

It is an arithmetic number, because the mean of its divisors is an integer number (199988407).

Almost surely, 2^399976813 is an apocalyptic number.

It is an amenable number.

399976813 is a deficient number, since it is larger than the sum of its proper divisors (1).

399976813 is an equidigital number, since it uses as much as digits as its factorization.

399976813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2204496, while the sum is 55.

The square root of 399976813 is about 19999.4203165992. The cubic root of 399976813 is about 736.7920625132.

The spelling of 399976813 in words is "three hundred ninety-nine million, nine hundred seventy-six thousand, eight hundred thirteen".