81159359400 has 1440 divisors, whose sum is σ = 357553722240. Its totient is φ = 16669255680.

The previous prime is 81159359341. The next prime is 81159359527. The reversal of 81159359400 is 495395118.

81159359400 is a `hidden beast` number, since 8 + 1 + 1 + 59 + 3 + 594 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 359 ways as a sum of consecutive naturals, for example, 2193496182 + ... + 2193496218.

It is an arithmetic number, because the mean of its divisors is an integer number (248301196).

Almost surely, 2^81159359400 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 81159359400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (178776861120).

81159359400 is an abundant number, since it is smaller than the sum of its proper divisors (276394362840).

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

81159359400 is a wasteful number, since it uses less digits than its factorization.

81159359400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153 (or 106 counting only the distinct ones).

The product of its (nonzero) digits is 194400, while the sum is 45.

The spelling of 81159359400 in words is "eighty-one billion, one hundred fifty-nine million, three hundred fifty-nine thousand, four hundred".