397693440 has 240 divisors, whose sum is σ = 1414268856. Its totient is φ = 103219200.

The previous prime is 397693411. The next prime is 397693469. The reversal of 397693440 is 44396793.

It is an interprime number because it is at equal distance from previous prime (397693411) and next prime (397693469).

It can be written as a sum of positive squares in 4 ways, for example, as 80568576 + 317124864 = 8976^2 + 17808^2 .

It is a tau number, because it is divible by the number of its divisors (240).

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 944430 + ... + 944850.

Almost surely, 2^397693440 is an apocalyptic number.

397693440 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 397693440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (707134428).

397693440 is an abundant number, since it is smaller than the sum of its proper divisors (1016575416).

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

397693440 is a wasteful number, since it uses less digits than its factorization.

397693440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 491 (or 472 counting only the distinct ones).

The product of its (nonzero) digits is 489888, while the sum is 45.

The square root of 397693440 is about 19942.2526310344. The cubic root of 397693440 is about 735.3873288228.

The spelling of 397693440 in words is "three hundred ninety-seven million, six hundred ninety-three thousand, four hundred forty".