397918440 has 64 divisors (see below), whose sum is σ = 1326398400. Its totient is φ = 106111296.

The previous prime is 397918429. The next prime is 397918441. The reversal of 397918440 is 44819793.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (397918441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 183142 + ... + 185301.

It is an arithmetic number, because the mean of its divisors is an integer number (20724975).

Almost surely, 2^397918440 is an apocalyptic number.

397918440 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

397918440 is an abundant number, since it is smaller than the sum of its proper divisors (928479960).

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

397918440 is a wasteful number, since it uses less digits than its factorization.

397918440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 368463 (or 368453 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 397918440 is about 19947.8931218312. The cubic root of 397918440 is about 735.5259875131.

The spelling of 397918440 in words is "three hundred ninety-seven million, nine hundred eighteen thousand, four hundred forty".