81287496 has 64 divisors (see below), whose sum is σ = 226800000. Its totient is φ = 26975808.

The previous prime is 81287467. The next prime is 81287593. The reversal of 81287496 is 69478218.

81287496 is a `hidden beast` number, since 81 + 2 + 87 + 496 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57405 + ... + 58803.

It is an arithmetic number, because the mean of its divisors is an integer number (3543750).

Almost surely, 2^81287496 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 81287496, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113400000).

81287496 is an abundant number, since it is smaller than the sum of its proper divisors (145512504).

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

81287496 is a wasteful number, since it uses less digits than its factorization.

81287496 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1683 (or 1673 counting only the distinct ones).

The product of its digits is 193536, while the sum is 45.

The square root of 81287496 is about 9015.9578526078. The cubic root of 81287496 is about 433.1861690936.

The spelling of 81287496 in words is "eighty-one million, two hundred eighty-seven thousand, four hundred ninety-six".