997447640 has 64 divisors (see below), whose sum is σ = 2577173760. Its totient is φ = 340341120.

The previous prime is 997447639. The next prime is 997447657. The reversal of 997447640 is 46744799.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50639 + ... + 67521.

It is an arithmetic number, because the mean of its divisors is an integer number (40268340).

Almost surely, 2^997447640 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 997447640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1288586880).

997447640 is an abundant number, since it is smaller than the sum of its proper divisors (1579726120).

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

997447640 is a wasteful number, since it uses less digits than its factorization.

997447640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17112 (or 17108 counting only the distinct ones).

The product of its (nonzero) digits is 1524096, while the sum is 50.

The square root of 997447640 is about 31582.3944627383. The cubic root of 997447640 is about 999.1484884672.

The spelling of 997447640 in words is "nine hundred ninety-seven million, four hundred forty-seven thousand, six hundred forty".