400866120 has 144 divisors (see below), whose sum is σ = 1384318260. Its totient is φ = 100583424.

The previous prime is 400866113. The next prime is 400866121. The reversal of 400866120 is 21668004.

400866120 is a `hidden beast` number, since 40 + 0 + 8 + 6 + 612 + 0 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 382358916 + 18507204 = 19554^2 + 4302^2 .

It is not an unprimeable number, because it can be changed into a prime (400866121) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 102114 + ... + 105966.

Almost surely, 2^400866120 is an apocalyptic number.

400866120 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 400866120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (692159130).

400866120 is an abundant number, since it is smaller than the sum of its proper divisors (983452140).

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

400866120 is a wasteful number, since it uses less digits than its factorization.

400866120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3904 (or 3880 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 400866120 is about 20021.6412913627. The cubic root of 400866120 is about 737.3377185790.

The spelling of 400866120 in words is "four hundred million, eight hundred sixty-six thousand, one hundred twenty".