1099991612520 has 96 divisors (see below), whose sum is σ = 3662167246920. Its totient is φ = 286176675840.

The previous prime is 1099991612519. The next prime is 1099991612539. The reversal of 1099991612520 is 252161999901.

1099991612520 is a `hidden beast` number, since 1 + 0 + 9 + 9 + 99 + 16 + 12 + 520 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 946639486116 + 153352126404 = 972954^2 + 391602^2 .

It is a super-2 number, since 2×1099991612520² (a number of 25 digits) contains 22 as substring.

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, 37247829 + ... + 37277348.

Almost surely, 2^{1099991612520} is an apocalyptic number.

1099991612520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1099991612520 is an abundant number, since it is smaller than the sum of its proper divisors (2562175634400).

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

1099991612520 is a wasteful number, since it uses less digits than its factorization.

1099991612520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74525235 (or 74525228 counting only the distinct ones).

The product of its (nonzero) digits is 787320, while the sum is 54.

The spelling of 1099991612520 in words is "one trillion, ninety-nine billion, nine hundred ninety-one million, six hundred twelve thousand, five hundred twenty".