397620840 has 128 divisors (see below), whose sum is σ = 1229385600. Its totient is φ = 102835200.

The previous prime is 397620823. The next prime is 397620841. The reversal of 397620840 is 48026793.

It is not an unprimeable number, because it can be changed into a prime (397620841) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 642051 + ... + 642669.

It is an arithmetic number, because the mean of its divisors is an integer number (9604575).

Almost surely, 2^397620840 is an apocalyptic number.

397620840 is a gapful number since it is divisible by the number (30) 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 397620840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (614692800).

397620840 is an abundant number, since it is smaller than the sum of its proper divisors (831764760).

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

397620840 is a wasteful number, since it uses less digits than its factorization.

397620840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 787 (or 783 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 39.

The square root of 397620840 is about 19940.4322922047. The cubic root of 397620840 is about 735.3425771256.

The spelling of 397620840 in words is "three hundred ninety-seven million, six hundred twenty thousand, eight hundred forty".