11572561998 has 36 divisors (see below), whose sum is σ = 25968349368. Its totient is φ = 3724497840.

The previous prime is 11572561967. The next prime is 11572561999. The reversal of 11572561998 is 89916527511.

It is a happy number.

11572561998 is a `hidden beast` number, since 1 + 1 + 5 + 72 + 561 + 9 + 9 + 8 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11572561999) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 367098 + ... + 397373.

It is an arithmetic number, because the mean of its divisors is an integer number (721343038).

Almost surely, 2^11572561998 is an apocalyptic number.

11572561998 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

11572561998 is an abundant number, since it is smaller than the sum of its proper divisors (14395787370).

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

11572561998 is a wasteful number, since it uses less digits than its factorization.

11572561998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 764537 (or 764505 counting only the distinct ones).

The product of its digits is 1360800, while the sum is 54.

The spelling of 11572561998 in words is "eleven billion, five hundred seventy-two million, five hundred sixty-one thousand, nine hundred ninety-eight".