400644642 has 16 divisors (see below), whose sum is σ = 801519552. Its totient is φ = 133509840.

The previous prime is 400644641. The next prime is 400644667. The reversal of 400644642 is 246446004.

It is a super-2 number, since 2×400644642² = 321032258326616328, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (400644641) 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, 20092 + ... + 34712.

It is an arithmetic number, because the mean of its divisors is an integer number (50094972).

Almost surely, 2^400644642 is an apocalyptic number.

400644642 is an abundant number, since it is smaller than the sum of its proper divisors (400874910).

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

400644642 is a wasteful number, since it uses less digits than its factorization.

400644642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19193.

The product of its (nonzero) digits is 18432, while the sum is 30.

The square root of 400644642 is about 20016.1095620503. The cubic root of 400644642 is about 737.2019008588.

The spelling of 400644642 in words is "four hundred million, six hundred forty-four thousand, six hundred forty-two".