400191640 has 32 divisors (see below), whose sum is σ = 901010880. Its totient is φ = 159973632.

The previous prime is 400191629. The next prime is 400191641. The reversal of 400191640 is 46191004.

400191640 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400191641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 102769 + ... + 106591.

It is an arithmetic number, because the mean of its divisors is an integer number (28156590).

Almost surely, 2^400191640 is an apocalyptic number.

400191640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

400191640 is an abundant number, since it is smaller than the sum of its proper divisors (500819240).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

400191640 is a wasteful number, since it uses less digits than its factorization.

400191640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6451 (or 6447 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 400191640 is about 20004.7904262954. The cubic root of 400191640 is about 736.9239489076.

The spelling of 400191640 in words is "four hundred million, one hundred ninety-one thousand, six hundred forty".