1011109991920 has 80 divisors (see below), whose sum is σ = 2686791748608. Its totient is φ = 346649760000.

The previous prime is 1011109991909. The next prime is 1011109991921. The reversal of 1011109991920 is 291999011101.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1011109991921) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20275657 + ... + 20325463.

Almost surely, 2^{1011109991920} is an apocalyptic number.

1011109991920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1011109991920 is an abundant number, since it is smaller than the sum of its proper divisors (1675681756688).

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

1011109991920 is a wasteful number, since it uses less digits than its factorization.

1011109991920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86078 (or 86072 counting only the distinct ones).

The product of its (nonzero) digits is 13122, while the sum is 43.

The spelling of 1011109991920 in words is "one trillion, eleven billion, one hundred nine million, nine hundred ninety-one thousand, nine hundred twenty".