400365640 has 32 divisors (see below), whose sum is σ = 953813880. Its totient is φ = 150725632.

The previous prime is 400365629. The next prime is 400365643. The reversal of 400365640 is 46563004.

It can be written as a sum of positive squares in 4 ways, for example, as 399440196 + 925444 = 19986^2 + 962^2 .

It is a junction number, because it is equal to n+sod(n) for n = 400365599 and 400365608.

It is not an unprimeable number, because it can be changed into a prime (400365643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 293707 + ... + 295066.

Almost surely, 2^400365640 is an apocalyptic number.

400365640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

400365640 is an abundant number, since it is smaller than the sum of its proper divisors (553448240).

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

400365640 is a wasteful number, since it uses less digits than its factorization.

400365640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 588801 (or 588797 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 28.

The square root of 400365640 is about 20009.1389120072. The cubic root of 400365640 is about 737.0307362357.

The spelling of 400365640 in words is "four hundred million, three hundred sixty-five thousand, six hundred forty".