11731564720 has 80 divisors (see below), whose sum is σ = 28328901120. Its totient is φ = 4514853632.

The previous prime is 11731564717. The next prime is 11731564721. The reversal of 11731564720 is 2746513711.

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

It is a super-2 number, since 2×11731564720² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 11731564720.

It is not an unprimeable number, because it can be changed into a prime (11731564721) 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, 195399 + ... + 248281.

It is an arithmetic number, because the mean of its divisors is an integer number (354111264).

Almost surely, 2^11731564720 is an apocalyptic number.

11731564720 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 11731564720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14164450560).

11731564720 is an abundant number, since it is smaller than the sum of its proper divisors (16597336400).

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

11731564720 is a wasteful number, since it uses less digits than its factorization.

11731564720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53002 (or 52996 counting only the distinct ones).

The product of its (nonzero) digits is 35280, while the sum is 37.

The spelling of 11731564720 in words is "eleven billion, seven hundred thirty-one million, five hundred sixty-four thousand, seven hundred twenty".