12121891620 has 48 divisors (see below), whose sum is σ = 33946321920. Its totient is φ = 3232025856.

The previous prime is 12121891619. The next prime is 12121891673. The reversal of 12121891620 is 2619812121.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 608376 + ... + 627984.

It is an arithmetic number, because the mean of its divisors is an integer number (707215040).

Almost surely, 2^12121891620 is an apocalyptic number.

12121891620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12121891620 is an abundant number, since it is smaller than the sum of its proper divisors (21824430300).

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

12121891620 is a wasteful number, since it uses less digits than its factorization.

12121891620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29924 (or 29922 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 33.

The spelling of 12121891620 in words is "twelve billion, one hundred twenty-one million, eight hundred ninety-one thousand, six hundred twenty".