991288130022 has 160 divisors (see below), whose sum is σ = 2349665708544. Its totient is φ = 311746406400.

The previous prime is 991288130009. The next prime is 991288130039. The reversal of 991288130022 is 220031882199.

It is a happy number.

It is a super-4 number, since 4×991288130022⁴ (a number of 49 digits) contains 4444 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 991288130022.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 81507622 + ... + 81519782.

Almost surely, 2^991288130022 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 991288130022, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1174832854272).

991288130022 is an abundant number, since it is smaller than the sum of its proper divisors (1358377578522).

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

991288130022 is a wasteful number, since it uses less digits than its factorization.

991288130022 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12496 (or 12487 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 45.

The spelling of 991288130022 in words is "nine hundred ninety-one billion, two hundred eighty-eight million, one hundred thirty thousand, twenty-two".