991253760 has 144 divisors (see below), whose sum is σ = 3618174336. Its totient is φ = 226566144.

The previous prime is 991253719. The next prime is 991253777. The reversal of 991253760 is 67352199.

It is a Harshad number since it is a multiple of its sum of digits (42).

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, 8442 + ... + 45318.

Almost surely, 2^991253760 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 991253760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1809087168).

991253760 is an abundant number, since it is smaller than the sum of its proper divisors (2626920576).

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

991253760 is a wasteful number, since it uses less digits than its factorization.

991253760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36908 (or 36894 counting only the distinct ones).

The product of its (nonzero) digits is 102060, while the sum is 42.

The square root of 991253760 is about 31484.1826954425. The cubic root of 991253760 is about 997.0760454895.

The spelling of 991253760 in words is "nine hundred ninety-one million, two hundred fifty-three thousand, seven hundred sixty".