400012640 has 48 divisors (see below), whose sum is σ = 946572480. Its totient is φ = 159744000.

The previous prime is 400012583. The next prime is 400012649. The reversal of 400012640 is 46210004.

400012640 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×400012640² = 320020224319539200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400012649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 118496 + ... + 121824.

It is an arithmetic number, because the mean of its divisors is an integer number (19720260).

Almost surely, 2^400012640 is an apocalyptic number.

400012640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

400012640 is an abundant number, since it is smaller than the sum of its proper divisors (546559840).

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

400012640 is a wasteful number, since it uses less digits than its factorization.

400012640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4095 (or 4087 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 400012640 is about 20000.3159975036. The cubic root of 400012640 is about 736.8140606727.

Adding to 400012640 its reverse (46210004), we get a palindrome (446222644).

The spelling of 400012640 in words is "four hundred million, twelve thousand, six hundred forty".