400790391 has 16 divisors (see below), whose sum is σ = 539816448. Its totient is φ = 264492000.

The previous prime is 400790359. The next prime is 400790417. The reversal of 400790391 is 193097004.

It is not a de Polignac number, because 400790391 - 2⁵ = 400790359 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400790591) 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 15 ways as a sum of consecutive naturals, for example, 142206 + ... + 144996.

It is an arithmetic number, because the mean of its divisors is an integer number (33738528).

Almost surely, 2^400790391 is an apocalyptic number.

400790391 is a deficient number, since it is larger than the sum of its proper divisors (139026057).

400790391 is a wasteful number, since it uses less digits than its factorization.

400790391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3262.

The product of its (nonzero) digits is 6804, while the sum is 33.

The square root of 400790391 is about 20019.7500234144. The cubic root of 400790391 is about 737.2912846518.

The spelling of 400790391 in words is "four hundred million, seven hundred ninety thousand, three hundred ninety-one".