297638640 has 120 divisors (see below), whose sum is σ = 1076493600. Its totient is φ = 73262592.

The previous prime is 297638633. The next prime is 297638651. The reversal of 297638640 is 46836792.

297638640 is a `hidden beast` number, since 2 + 9 + 7 + 638 + 6 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (120).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6540 + ... + 25259.

It is an arithmetic number, because the mean of its divisors is an integer number (8970780).

Almost surely, 2^297638640 is an apocalyptic number.

297638640 is a gapful number since it is divisible by the number (20) 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 297638640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (538246800).

297638640 is an abundant number, since it is smaller than the sum of its proper divisors (778854960).

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

297638640 is a wasteful number, since it uses less digits than its factorization.

297638640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31831 (or 31822 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 45.

The square root of 297638640 is about 17252.2068153613. The cubic root of 297638640 is about 667.6719079176.

It can be divided in two parts, 2976 and 38640, that added together give a triangular number (41616 = T₂₈₈).

The spelling of 297638640 in words is "two hundred ninety-seven million, six hundred thirty-eight thousand, six hundred forty".