81153274356 has 168 divisors, whose sum is σ = 265471827264. Its totient is φ = 21078714240.

The previous prime is 81153274339. The next prime is 81153274361. The reversal of 81153274356 is 65347235118.

It is a happy number.

81153274356 is a `hidden beast` number, since 8 + 11 + 532 + 74 + 35 + 6 = 666.

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 55 ways as a sum of consecutive naturals, for example, 43816 + ... + 405248.

It is an arithmetic number, because the mean of its divisors is an integer number (1580189448).

Almost surely, 2^81153274356 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 81153274356, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (132735913632).

81153274356 is an abundant number, since it is smaller than the sum of its proper divisors (184318552908).

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

81153274356 is a wasteful number, since it uses less digits than its factorization.

81153274356 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 361473 (or 361456 counting only the distinct ones).

The product of its digits is 604800, while the sum is 45.

The spelling of 81153274356 in words is "eighty-one billion, one hundred fifty-three million, two hundred seventy-four thousand, three hundred fifty-six".