400165640 has 32 divisors (see below), whose sum is σ = 1028998080. Its totient is φ = 137199552.

The previous prime is 400165603. The next prime is 400165651. The reversal of 400165640 is 46561004.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 714302 + ... + 714861.

It is an arithmetic number, because the mean of its divisors is an integer number (32156190).

Almost surely, 2^400165640 is an apocalyptic number.

400165640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

400165640 is an abundant number, since it is smaller than the sum of its proper divisors (628832440).

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

400165640 is a wasteful number, since it uses less digits than its factorization.

400165640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1429181 (or 1429177 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 400165640 is about 20004.1405713917. The cubic root of 400165640 is about 736.9079895224.

The spelling of 400165640 in words is "four hundred million, one hundred sixty-five thousand, six hundred forty".