400378779 has 24 divisors (see below), whose sum is σ = 613716480. Its totient is φ = 250978992.

The previous prime is 400378777. The next prime is 400378789. The reversal of 400378779 is 977873004.

It is not a de Polignac number, because 400378779 - 2¹ = 400378777 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (400378777) 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 23 ways as a sum of consecutive naturals, for example, 4179 + ... + 28604.

It is an arithmetic number, because the mean of its divisors is an integer number (25571520).

Almost surely, 2^400378779 is an apocalyptic number.

400378779 is a deficient number, since it is larger than the sum of its proper divisors (213337701).

400378779 is a wasteful number, since it uses less digits than its factorization.

400378779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32871 (or 32868 counting only the distinct ones).

The product of its (nonzero) digits is 296352, while the sum is 45.

The square root of 400378779 is about 20009.4672342869. The cubic root of 400378779 is about 737.0387986499.

The spelling of 400378779 in words is "four hundred million, three hundred seventy-eight thousand, seven hundred seventy-nine".