400493991 has 16 divisors (see below), whose sum is σ = 552268800. Its totient is φ = 257890560.

The previous prime is 400493927. The next prime is 400493999. The reversal of 400493991 is 199394004.

It is not a de Polignac number, because 400493991 - 2⁶ = 400493927 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400493999) 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, 48535 + ... + 56183.

It is an arithmetic number, because the mean of its divisors is an integer number (34516800).

Almost surely, 2^400493991 is an apocalyptic number.

400493991 is a deficient number, since it is larger than the sum of its proper divisors (151774809).

400493991 is a wasteful number, since it uses less digits than its factorization.

400493991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8246.

The product of its (nonzero) digits is 34992, while the sum is 39.

The square root of 400493991 is about 20012.3459644291. The cubic root of 400493991 is about 737.1094880194.

The spelling of 400493991 in words is "four hundred million, four hundred ninety-three thousand, nine hundred ninety-one".