400007939 has 2 divisors, whose sum is σ = 400007940. Its totient is φ = 400007938.

The previous prime is 400007917. The next prime is 400007941. The reversal of 400007939 is 939700004.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 400007939 - 2²⁴ = 383230723 is a prime.

Together with 400007941, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (400006939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200003969 + 200003970.

It is an arithmetic number, because the mean of its divisors is an integer number (200003970).

Almost surely, 2^400007939 is an apocalyptic number.

400007939 is a deficient number, since it is larger than the sum of its proper divisors (1).

400007939 is an equidigital number, since it uses as much as digits as its factorization.

400007939 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6804, while the sum is 32.

The square root of 400007939 is about 20000.1984740152. The cubic root of 400007939 is about 736.8111742835.

It can be divided in two parts, 400007 and 939, that multiplied together give a palindrome (375606573).

The spelling of 400007939 in words is "four hundred million, seven thousand, nine hundred thirty-nine".