81601228800 has 1404 divisors, whose sum is σ = 368784703560. Its totient is φ = 17093099520.

The previous prime is 81601228789. The next prime is 81601228883. The reversal of 81601228800 is 882210618.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 587059131 + ... + 587059269.

Almost surely, 2^81601228800 is an apocalyptic number.

81601228800 is a gapful number since it is divisible by the number (80) 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 81601228800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (184392351780).

81601228800 is an abundant number, since it is smaller than the sum of its proper divisors (287183474760).

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

81601228800 is a wasteful number, since it uses less digits than its factorization.

81601228800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206 (or 169 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 36.

The spelling of 81601228800 in words is "eighty-one billion, six hundred one million, two hundred twenty-eight thousand, eight hundred".