400512779 has 2 divisors, whose sum is σ = 400512780. Its totient is φ = 400512778.

The previous prime is 400512757. The next prime is 400512781. The reversal of 400512779 is 977215004.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 400512779 - 2²⁰ = 399464203 is a prime.

It is a super-2 number, since 2×400512779² = 320820972284605682, which contains 22 as substring.

Together with 400512781, 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 (400512379) 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 as a sum of consecutive naturals, namely, 200256389 + 200256390.

It is an arithmetic number, because the mean of its divisors is an integer number (200256390).

Almost surely, 2^400512779 is an apocalyptic number.

400512779 is a deficient number, since it is larger than the sum of its proper divisors (1).

400512779 is an equidigital number, since it uses as much as digits as its factorization.

400512779 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17640, while the sum is 35.

The square root of 400512779 is about 20012.8153691578. The cubic root of 400512779 is about 737.1210142818.

The spelling of 400512779 in words is "four hundred million, five hundred twelve thousand, seven hundred seventy-nine".