81493776 has 200 divisors, whose sum is σ = 290717504. Its totient is φ = 21461760.

The previous prime is 81493751. The next prime is 81493777. The reversal of 81493776 is 67739418.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (81493777) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 117591 + ... + 118281.

Almost surely, 2^81493776 is an apocalyptic number.

81493776 is the 7371-st pentagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81493776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145358752).

81493776 is an abundant number, since it is smaller than the sum of its proper divisors (209223728).

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

81493776 is a wasteful number, since it uses less digits than its factorization.

81493776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 731 (or 716 counting only the distinct ones).

The product of its digits is 254016, while the sum is 45.

The square root of 81493776 is about 9027.3903205744. The cubic root of 81493776 is about 433.5522859312.

The spelling of 81493776 in words is "eighty-one million, four hundred ninety-three thousand, seven hundred seventy-six".