81235156884 has 96 divisors (see below), whose sum is σ = 218950373376. Its totient is φ = 22961500800.

The previous prime is 81235156883. The next prime is 81235156907. The reversal of 81235156884 is 48865153218.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81235156883) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12917989 + ... + 12924275.

It is an arithmetic number, because the mean of its divisors is an integer number (2280733056).

Almost surely, 2^81235156884 is an apocalyptic number.

81235156884 is a gapful number since it is divisible by the number (84) 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 81235156884, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109475186688).

81235156884 is an abundant number, since it is smaller than the sum of its proper divisors (137715216492).

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

81235156884 is a wasteful number, since it uses less digits than its factorization.

81235156884 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7925 (or 7923 counting only the distinct ones).

The product of its digits is 1843200, while the sum is 51.

The spelling of 81235156884 in words is "eighty-one billion, two hundred thirty-five million, one hundred fifty-six thousand, eight hundred eighty-four".