991148788 has 48 divisors (see below), whose sum is σ = 2021443200. Its totient is φ = 416430720.

The previous prime is 991148783. The next prime is 991148791. The reversal of 991148788 is 887841199.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991148783) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 893178 + ... + 894286.

It is an arithmetic number, because the mean of its divisors is an integer number (42113400).

Almost surely, 2^991148788 is an apocalyptic number.

It is an amenable number.

991148788 is an abundant number, since it is smaller than the sum of its proper divisors (1030294412).

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

991148788 is a wasteful number, since it uses less digits than its factorization.

991148788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1720 (or 1718 counting only the distinct ones).

The product of its digits is 1161216, while the sum is 55.

The square root of 991148788 is about 31482.5155919917. The cubic root of 991148788 is about 997.0408480571.

It can be divided in two parts, 991148 and 788, that added together give a triangular number (991936 = T₁₄₀₈).

The spelling of 991148788 in words is "nine hundred ninety-one million, one hundred forty-eight thousand, seven hundred eighty-eight".