399920951 has 4 divisors (see below), whose sum is σ = 400871304. Its totient is φ = 398970600.

The previous prime is 399920893. The next prime is 399921013. The reversal of 399920951 is 159029993.

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 399920951 - 2¹⁴ = 399904567 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 399920896 and 399920905.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399925951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 474545 + ... + 475386.

It is an arithmetic number, because the mean of its divisors is an integer number (100217826).

Almost surely, 2^399920951 is an apocalyptic number.

399920951 is a deficient number, since it is larger than the sum of its proper divisors (950353).

399920951 is an equidigital number, since it uses as much as digits as its factorization.

399920951 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 950352.

The product of its (nonzero) digits is 196830, while the sum is 47.

The square root of 399920951 is about 19998.0236773537. The cubic root of 399920951 is about 736.7577600294.

The spelling of 399920951 in words is "three hundred ninety-nine million, nine hundred twenty thousand, nine hundred fifty-one".