81117529200 has 90 divisors (see below), whose sum is σ = 281500371464. Its totient is φ = 21631340160.

The previous prime is 81117529187. The next prime is 81117529201. The reversal of 81117529200 is 292571118.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (90).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81117529201) 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, 11262724 + ... + 11269923.

Almost surely, 2^81117529200 is an apocalyptic number.

81117529200 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81117529200 is an abundant number, since it is smaller than the sum of its proper divisors (200382842264).

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

81117529200 is a wasteful number, since it uses less digits than its factorization.

81117529200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22532671 (or 22532657 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 36.

The spelling of 81117529200 in words is "eighty-one billion, one hundred seventeen million, five hundred twenty-nine thousand, two hundred".