400288820 has 24 divisors (see below), whose sum is σ = 853155744. Its totient is φ = 157725216.

The previous prime is 400288799. The next prime is 400288853. The reversal of 400288820 is 28882004.

It is a super-2 number, since 2×400288820² = 320462278833984800, which contains 22 as substring.

It is a congruent number.

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, 148022 + ... + 150701.

It is an arithmetic number, because the mean of its divisors is an integer number (35548156).

Almost surely, 2^400288820 is an apocalyptic number.

It is an amenable number.

400288820 is an abundant number, since it is smaller than the sum of its proper divisors (452866924).

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

400288820 is a wasteful number, since it uses less digits than its factorization.

400288820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 298799 (or 298797 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 32.

The square root of 400288820 is about 20007.2191970798. The cubic root of 400288820 is about 736.9835940594.

The spelling of 400288820 in words is "four hundred million, two hundred eighty-eight thousand, eight hundred twenty".