12891985920 has 672 divisors, whose sum is σ = 50917098960. Its totient is φ = 3105423360.

The previous prime is 12891985913. The next prime is 12891985969. The reversal of 12891985920 is 2958919821.

It is a super-2 number, since 2×12891985920² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 82114482 + ... + 82114638.

Almost surely, 2^12891985920 is an apocalyptic number.

12891985920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12891985920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25458549480).

12891985920 is an abundant number, since it is smaller than the sum of its proper divisors (38025113040).

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

12891985920 is an equidigital number, since it uses as much as digits as its factorization.

12891985920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213 (or 178 counting only the distinct ones).

The product of its (nonzero) digits is 933120, while the sum is 54.

The spelling of 12891985920 in words is "twelve billion, eight hundred ninety-one million, nine hundred eighty-five thousand, nine hundred twenty".