400081642 has 12 divisors (see below), whose sum is σ = 627350850. Its totient is φ = 191342888.

The previous prime is 400081639. The next prime is 400081679. The reversal of 400081642 is 246180004.

It can be written as a sum of positive squares in only one way, i.e., 332661121 + 67420521 = 18239^2 + 8211^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 188017 + ... + 190132.

Almost surely, 2^400081642 is an apocalyptic number.

400081642 is a deficient number, since it is larger than the sum of its proper divisors (227269208).

400081642 is a wasteful number, since it uses less digits than its factorization.

400081642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 378197 (or 378174 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 25.

The square root of 400081642 is about 20002.0409458635. The cubic root of 400081642 is about 736.8564249346.

The spelling of 400081642 in words is "four hundred million, eighty-one thousand, six hundred forty-two".