11491973820 has 120 divisors (see below), whose sum is σ = 38171471184. Its totient is φ = 2884253184.

The previous prime is 11491973797. The next prime is 11491973833. The reversal of 11491973820 is 2837919411.

11491973820 is a `hidden beast` number, since 11 + 491 + 9 + 73 + 82 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 181102 + ... + 236181.

Almost surely, 2^11491973820 is an apocalyptic number.

11491973820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

11491973820 is an abundant number, since it is smaller than the sum of its proper divisors (26679497364).

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

11491973820 is a wasteful number, since it uses less digits than its factorization.

11491973820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 417321 (or 417310 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 45.

The spelling of 11491973820 in words is "eleven billion, four hundred ninety-one million, nine hundred seventy-three thousand, eight hundred twenty".