991636002 has 96 divisors (see below), whose sum is σ = 2505634560. Its totient is φ = 277603200.

The previous prime is 991635971. The next prime is 991636013. The reversal of 991636002 is 200636199.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1414252 + ... + 1414952.

It is an arithmetic number, because the mean of its divisors is an integer number (26100360).

Almost surely, 2^991636002 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 991636002, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1252817280).

991636002 is an abundant number, since it is smaller than the sum of its proper divisors (1513998558).

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

991636002 is a wasteful number, since it uses less digits than its factorization.

991636002 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 928 (or 925 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 36.

The square root of 991636002 is about 31490.2524918426. The cubic root of 991636002 is about 997.2041914055.

The spelling of 991636002 in words is "nine hundred ninety-one million, six hundred thirty-six thousand, two".