81241187800 has 96 divisors (see below), whose sum is σ = 203770663200. Its totient is φ = 30007777280.

The previous prime is 81241187773. The next prime is 81241187813. The reversal of 81241187800 is 878114218.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 45220 + ... + 405619.

It is an arithmetic number, because the mean of its divisors is an integer number (2122611075).

Almost surely, 2^81241187800 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81241187800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101885331600).

81241187800 is an abundant number, since it is smaller than the sum of its proper divisors (122529475400).

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

81241187800 is a wasteful number, since it uses less digits than its factorization.

81241187800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 450925 (or 450916 counting only the distinct ones).

The product of its (nonzero) digits is 28672, while the sum is 40.

The spelling of 81241187800 in words is "eighty-one billion, two hundred forty-one million, one hundred eighty-seven thousand, eight hundred".