991245760 has 56 divisors (see below), whose sum is σ = 2388906576. Its totient is φ = 391710720.

The previous prime is 991245737. The next prime is 991245767. The reversal of 991245760 is 67542199.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991245767) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7900 + ... + 45220.

It is an arithmetic number, because the mean of its divisors is an integer number (42659046).

Almost surely, 2^991245760 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 991245760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1194453288).

991245760 is an abundant number, since it is smaller than the sum of its proper divisors (1397660816).

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

991245760 is a wasteful number, since it uses less digits than its factorization.

991245760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37421 (or 37411 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 43.

The square root of 991245760 is about 31484.0556472637. The cubic root of 991245760 is about 997.0733631525.

The spelling of 991245760 in words is "nine hundred ninety-one million, two hundred forty-five thousand, seven hundred sixty".