991872036 has 81 divisors (see below), whose sum is σ = 2611095123. Its totient is φ = 317459520.

The previous prime is 991872031. The next prime is 991872047. The reversal of 991872036 is 630278199.

The square root of 991872036 is 31494.

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

It can be written as a sum of positive squares in 4 ways, for example, as 368870436 + 623001600 = 19206^2 + 24960^2 .

It is a junction number, because it is equal to n+sod(n) for n = 991871982 and 991872000.

It is not an unprimeable number, because it can be changed into a prime (991872031) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 5479866 + ... + 5480046.

Almost surely, 2^991872036 is an apocalyptic number.

991872036 is the 31494-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 991872036

991872036 is an abundant number, since it is smaller than the sum of its proper divisors (1619223087).

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

991872036 is a wasteful number, since it uses less digits than its factorization.

991872036 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 430 (or 215 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 45.

The cubic root of 991872036 is about 997.2833049180.

The spelling of 991872036 in words is "nine hundred ninety-one million, eight hundred seventy-two thousand, thirty-six".