991645522596 has 117 divisors (see below), whose sum is σ = 2606884670971. Its totient is φ = 330064541928.

The previous prime is 991645522591. The next prime is 991645522603. The reversal of 991645522596 is 695225546199.

The square root of 991645522596 is 995814.

It is a perfect power (a square), and thus also a powerful number.

991645522596 is a `hidden beast` number, since 9 + 9 + 16 + 4 + 5 + 5 + 22 + 596 = 666.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (991645522591) by changing a digit.

It is a polite number, since it can be written in 38 ways as a sum of consecutive naturals, for example, 1451896471 + ... + 1451897153.

Almost surely, 2^991645522596 is an apocalyptic number.

991645522596 is the 995814-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 991645522596

991645522596 is an abundant number, since it is smaller than the sum of its proper divisors (1615239148375).

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

991645522596 is an frugal number, since it uses more digits than its factorization.

With its predecessor (991645522595) it forms an eRAP, since the sums of their prime factors are consecutive (1405 and 1406).

991645522596 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1406 (or 688 counting only the distinct ones).

The product of its digits is 52488000, while the sum is 63.

The spelling of 991645522596 in words is "nine hundred ninety-one billion, six hundred forty-five million, five hundred twenty-two thousand, five hundred ninety-six".