400105640 has 32 divisors (see below), whose sum is σ = 982078560. Its totient is φ = 145492800.

The previous prime is 400105579. The next prime is 400105681. The reversal of 400105640 is 46501004.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 454226 + ... + 455105.

It is an arithmetic number, because the mean of its divisors is an integer number (30689955).

Almost surely, 2^400105640 is an apocalyptic number.

400105640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

400105640 is an abundant number, since it is smaller than the sum of its proper divisors (581972920).

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

400105640 is a wasteful number, since it uses less digits than its factorization.

400105640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 909353 (or 909349 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 400105640 is about 20002.6408256510. The cubic root of 400105640 is about 736.8711575333.

Adding to 400105640 its reverse (46501004), we get a palindrome (446606644).

The spelling of 400105640 in words is "four hundred million, one hundred five thousand, six hundred forty".