397853840 has 40 divisors (see below), whose sum is σ = 931246200. Its totient is φ = 158068736.

The previous prime is 397853801. The next prime is 397853849. The reversal of 397853840 is 48358793.

It can be written as a sum of positive squares in 4 ways, for example, as 19784704 + 378069136 = 4448^2 + 19444^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (397853849) 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, 4769 + ... + 28608.

It is an arithmetic number, because the mean of its divisors is an integer number (23281155).

Almost surely, 2^397853840 is an apocalyptic number.

It is an amenable number.

397853840 is an abundant number, since it is smaller than the sum of its proper divisors (533392360).

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

397853840 is a wasteful number, since it uses less digits than its factorization.

397853840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33539 (or 33533 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 47.

The square root of 397853840 is about 19946.2738374865. The cubic root of 397853840 is about 735.4861824128.

The spelling of 397853840 in words is "three hundred ninety-seven million, eight hundred fifty-three thousand, eight hundred forty".