400439644 has 12 divisors (see below), whose sum is σ = 764475768. Its totient is φ = 182018000.

The previous prime is 400439639. The next prime is 400439659. The reversal of 400439644 is 446934004.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4550407 + ... + 4550494.

It is an arithmetic number, because the mean of its divisors is an integer number (63706314).

Almost surely, 2^400439644 is an apocalyptic number.

400439644 is a gapful number since it is divisible by the number (44) formed by its first and last digit.

It is an amenable number.

400439644 is a deficient number, since it is larger than the sum of its proper divisors (364036124).

400439644 is a wasteful number, since it uses less digits than its factorization.

400439644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9100916 (or 9100914 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 34.

The square root of 400439644 is about 20010.9880815516. The cubic root of 400439644 is about 737.0761446132.

It can be divided in two parts, 400 and 439644, that added together give a palindrome (440044).

The spelling of 400439644 in words is "four hundred million, four hundred thirty-nine thousand, six hundred forty-four".