991387060 has 12 divisors (see below), whose sum is σ = 2081912868. Its totient is φ = 396554816.

The previous prime is 991387043. The next prime is 991387151. The reversal of 991387060 is 60783199.

It can be written as a sum of positive squares in 2 ways, for example, as 245987856 + 745399204 = 15684^2 + 27302^2 .

It is a junction number, because it is equal to n+sod(n) for n = 991386998 and 991387016.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24784657 + ... + 24784696.

It is an arithmetic number, because the mean of its divisors is an integer number (173492739).

Almost surely, 2^991387060 is an apocalyptic number.

It is an amenable number.

991387060 is an abundant number, since it is smaller than the sum of its proper divisors (1090525808).

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

991387060 is a wasteful number, since it uses less digits than its factorization.

991387060 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49569362 (or 49569360 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 43.

The square root of 991387060 is about 31486.2995602849. The cubic root of 991387060 is about 997.1207378057.

The spelling of 991387060 in words is "nine hundred ninety-one million, three hundred eighty-seven thousand, sixty".