397533440 has 72 divisors (see below), whose sum is σ = 1008284760. Its totient is φ = 149651456.

The previous prime is 397533427. The next prime is 397533469. The reversal of 397533440 is 44335793.

It can be written as a sum of positive squares in 4 ways, for example, as 121176064 + 276357376 = 11008^2 + 16624^2 .

It is a junction number, because it is equal to n+sod(n) for n = 397533394 and 397533403.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12626 + ... + 30894.

It is an arithmetic number, because the mean of its divisors is an integer number (14003955).

Almost surely, 2^397533440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 397533440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (504142380).

397533440 is an abundant number, since it is smaller than the sum of its proper divisors (610751320).

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

397533440 is a wasteful number, since it uses less digits than its factorization.

397533440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18307 (or 18293 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 38.

The square root of 397533440 is about 19938.2406445504. The cubic root of 397533440 is about 735.2886952661.

The spelling of 397533440 in words is "three hundred ninety-seven million, five hundred thirty-three thousand, four hundred forty".