400138984 has 32 divisors (see below), whose sum is σ = 887011200. Its totient is φ = 165574080.

The previous prime is 400138961. The next prime is 400139017. The reversal of 400138984 is 489831004.

It is a super-2 number, since 2×400138984² = 320222413033104512, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 121572 + ... + 124819.

It is an arithmetic number, because the mean of its divisors is an integer number (27719100).

Almost surely, 2^400138984 is an apocalyptic number.

It is an amenable number.

400138984 is an abundant number, since it is smaller than the sum of its proper divisors (486872216).

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

400138984 is a wasteful number, since it uses less digits than its factorization.

400138984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246433 (or 246429 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 37.

The square root of 400138984 is about 20003.4742982313. The cubic root of 400138984 is about 736.8916267519.

Adding to 400138984 its reverse (489831004), we get a palindrome (889969988).

The spelling of 400138984 in words is "four hundred million, one hundred thirty-eight thousand, nine hundred eighty-four".