400866020 has 24 divisors (see below), whose sum is σ = 862352568. Its totient is φ = 156435200.

The previous prime is 400866007. The next prime is 400866023. The reversal of 400866020 is 20668004.

It can be written as a sum of positive squares in 4 ways, for example, as 37429924 + 363436096 = 6118^2 + 19064^2 .

It is not an unprimeable number, because it can be changed into a prime (400866023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 243611 + ... + 245250.

It is an arithmetic number, because the mean of its divisors is an integer number (35931357).

Almost surely, 2^400866020 is an apocalyptic number.

It is an amenable number.

400866020 is an abundant number, since it is smaller than the sum of its proper divisors (461486548).

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

400866020 is a wasteful number, since it uses less digits than its factorization.

400866020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 488911 (or 488909 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 400866020 is about 20021.6387940648. The cubic root of 400866020 is about 737.3376572669.

The spelling of 400866020 in words is "four hundred million, eight hundred sixty-six thousand, twenty".