81653376 has 128 divisors (see below), whose sum is σ = 254885760. Its totient is φ = 22671360.

The previous prime is 81653359. The next prime is 81653387. The reversal of 81653376 is 67335618.

It is a tau number, because it is divible by the number of its divisors (128).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 99046 + ... + 99866.

It is an arithmetic number, because the mean of its divisors is an integer number (1991295).

Almost surely, 2^81653376 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 81653376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (127442880).

81653376 is an abundant number, since it is smaller than the sum of its proper divisors (173232384).

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

81653376 is a wasteful number, since it uses less digits than its factorization.

81653376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 882 (or 870 counting only the distinct ones).

The product of its digits is 90720, while the sum is 39.

The square root of 81653376 is about 9036.2257607919. The cubic root of 81653376 is about 433.8351288923.

The spelling of 81653376 in words is "eighty-one million, six hundred fifty-three thousand, three hundred seventy-six".