11971242720 has 480 divisors, whose sum is σ = 44259747840. Its totient is φ = 3043630080.

The previous prime is 11971242719. The next prime is 11971242743. The reversal of 11971242720 is 2724217911.

It is a tau number, because it is divible by the number of its divisors (480).

It is a super-2 number, since 2×11971242720² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 33345901 + ... + 33346259.

It is an arithmetic number, because the mean of its divisors is an integer number (92207808).

Almost surely, 2^11971242720 is an apocalyptic number.

11971242720 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 11971242720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22129873920).

11971242720 is an abundant number, since it is smaller than the sum of its proper divisors (32288505120).

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

11971242720 is a wasteful number, since it uses less digits than its factorization.

11971242720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 500 (or 483 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The spelling of 11971242720 in words is "eleven billion, nine hundred seventy-one million, two hundred forty-two thousand, seven hundred twenty".