991247240 has 32 divisors (see below), whose sum is σ = 2239899480. Its totient is φ = 394793472.

The previous prime is 991247239. The next prime is 991247267. The reversal of 991247240 is 42742199.

991247240 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 926958916 + 64288324 = 30446^2 + 8018^2 .

It is a junction number, because it is equal to n+sod(n) for n = 991247194 and 991247203.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43859 + ... + 62498.

Almost surely, 2^991247240 is an apocalyptic number.

It is an amenable number.

991247240 is an abundant number, since it is smaller than the sum of its proper divisors (1248652240).

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

991247240 is a wasteful number, since it uses less digits than its factorization.

991247240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106601 (or 106597 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 38.

The square root of 991247240 is about 31484.0791512155. The cubic root of 991247240 is about 997.0738593859.

The spelling of 991247240 in words is "nine hundred ninety-one million, two hundred forty-seven thousand, two hundred forty".