11972817920 has 176 divisors, whose sum is σ = 33030523008. Its totient is φ = 4079124480.

The previous prime is 11972817917. The next prime is 11972817937. The reversal of 11972817920 is 2971827911.

It is a congruent number.

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, 6199355 + ... + 6201285.

Almost surely, 2^11972817920 is an apocalyptic number.

11972817920 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 11972817920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16515261504).

11972817920 is an abundant number, since it is smaller than the sum of its proper divisors (21057705088).

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

11972817920 is a wasteful number, since it uses less digits than its factorization.

11972817920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2136 (or 2118 counting only the distinct ones).

The product of its (nonzero) digits is 127008, while the sum is 47.

Subtracting from 11972817920 its reverse (2971827911), we obtain a palindrome (9000990009).

The spelling of 11972817920 in words is "eleven billion, nine hundred seventy-two million, eight hundred seventeen thousand, nine hundred twenty".