400117640 has 128 divisors (see below), whose sum is σ = 1015308000. Its totient is φ = 141732864.

The previous prime is 400117639. The next prime is 400117657. The reversal of 400117640 is 46711004.

It can be written as a sum of positive squares in 16 ways, for example, as 186431716 + 213685924 = 13654^2 + 14618^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2548442 + ... + 2548598.

Almost surely, 2^400117640 is an apocalyptic number.

400117640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 400117640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (507654000).

400117640 is an abundant number, since it is smaller than the sum of its proper divisors (615190360).

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

400117640 is a wasteful number, since it uses less digits than its factorization.

400117640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236 (or 206 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 400117640 is about 20002.9407837948. The cubic root of 400117640 is about 736.8785242257.

Adding to 400117640 its reverse (46711004), we get a palindrome (446828644).

The spelling of 400117640 in words is "four hundred million, one hundred seventeen thousand, six hundred forty".