397309440 has 160 divisors (see below), whose sum is σ = 1385911296. Its totient is φ = 96296960.

The previous prime is 397309433. The next prime is 397309447. The reversal of 397309440 is 44903793.

It is an interprime number because it is at equal distance from previous prime (397309433) and next prime (397309447).

It is a tau number, because it is divible by the number of its divisors (160).

It is a super-2 number, since 2×397309440² = 315709582226227200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (397309447) 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, 82129 + ... + 86831.

Almost surely, 2^397309440 is an apocalyptic number.

397309440 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 397309440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (692955648).

397309440 is an abundant number, since it is smaller than the sum of its proper divisors (988601856).

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

397309440 is a wasteful number, since it uses less digits than its factorization.

397309440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4740 (or 4724 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 39.

The square root of 397309440 is about 19932.6225068354. The cubic root of 397309440 is about 735.1505638147.

The spelling of 397309440 in words is "three hundred ninety-seven million, three hundred nine thousand, four hundred forty".