991426313522 has 6 divisors (see below), whose sum is σ = 1487141582493. Its totient is φ = 495712452692.

The previous prime is 991426313497. The next prime is 991426313543. The reversal of 991426313522 is 225313624199.

It can be written as a sum of positive squares in 2 ways, for example, as 648731982721 + 342694330801 = 805439^2 + 585401^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=704069.

It is a super-2 number, since 2×991426313522² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 1056104 + ... + 1760172.

Almost surely, 2^991426313522 is an apocalyptic number.

991426313522 is a deficient number, since it is larger than the sum of its proper divisors (495715268971).

991426313522 is an frugal number, since it uses more digits than its factorization.

991426313522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1408140 (or 704071 counting only the distinct ones).

The product of its digits is 699840, while the sum is 47.

The spelling of 991426313522 in words is "nine hundred ninety-one billion, four hundred twenty-six million, three hundred thirteen thousand, five hundred twenty-two".