991613952 has 264 divisors, whose sum is σ = 3448785600. Its totient is φ = 268075008.

The previous prime is 991613947. The next prime is 991613963. The reversal of 991613952 is 259316199.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 991613898 and 991613907.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1225324 + ... + 1226132.

Almost surely, 2^991613952 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 991613952, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1724392800).

991613952 is an abundant number, since it is smaller than the sum of its proper divisors (2457171648).

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

991613952 is a wasteful number, since it uses less digits than its factorization.

991613952 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 861 (or 840 counting only the distinct ones).

The product of its digits is 131220, while the sum is 45.

The square root of 991613952 is about 31489.9023815572. The cubic root of 991613952 is about 997.1968000793.

The spelling of 991613952 in words is "nine hundred ninety-one million, six hundred thirteen thousand, nine hundred fifty-two".