400087998 has 20 divisors (see below), whose sum is σ = 896493840. Its totient is φ = 133362612.

The previous prime is 400087969. The next prime is 400087999. The reversal of 400087998 is 899780004.

It is a super-2 number, since 2×400087998² = 320140812287296008, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400087999) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1234678 + ... + 1235001.

It is an arithmetic number, because the mean of its divisors is an integer number (44824692).

Almost surely, 2^400087998 is an apocalyptic number.

400087998 is an abundant number, since it is smaller than the sum of its proper divisors (496405842).

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

400087998 is a wasteful number, since it uses less digits than its factorization.

400087998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2469693 (or 2469684 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 400087998 is about 20002.1998290188. The cubic root of 400087998 is about 736.8603270003.

The spelling of 400087998 in words is "four hundred million, eighty-seven thousand, nine hundred ninety-eight".