991122240 has 56 divisors (see below), whose sum is σ = 3146816160. Its totient is φ = 264299008.

The previous prime is 991122227. The next prime is 991122247. The reversal of 991122240 is 42221199.

It is a happy number.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 991122198 and 991122207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991122247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 515250 + ... + 517169.

Almost surely, 2^991122240 is an apocalyptic number.

It is an amenable number.

991122240 is an abundant number, since it is smaller than the sum of its proper divisors (2155693920).

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

991122240 is a wasteful number, since it uses less digits than its factorization.

991122240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1032439 (or 1032429 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 991122240 is about 31482.0939583122. The cubic root of 991122240 is about 997.0319460379.

The spelling of 991122240 in words is "nine hundred ninety-one million, one hundred twenty-two thousand, two hundred forty".