11661721752 has 32 divisors (see below), whose sum is σ = 29217300480. Its totient is φ = 3878841120.

The previous prime is 11661721699. The next prime is 11661721777. The reversal of 11661721752 is 25712716611.

It is a self number, because there is not a number n which added to its sum of digits gives 11661721752.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 513624 + ... + 535847.

It is an arithmetic number, because the mean of its divisors is an integer number (913040640).

Almost surely, 2^11661721752 is an apocalyptic number.

11661721752 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

11661721752 is an abundant number, since it is smaller than the sum of its proper divisors (17555578728).

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

11661721752 is a wasteful number, since it uses less digits than its factorization.

11661721752 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1049943 (or 1049939 counting only the distinct ones).

The product of its digits is 35280, while the sum is 39.

The spelling of 11661721752 in words is "eleven billion, six hundred sixty-one million, seven hundred twenty-one thousand, seven hundred fifty-two".