81519552 has 84 divisors (see below), whose sum is σ = 234930696. Its totient is φ = 27025920.

The previous prime is 81519541. The next prime is 81519577. The reversal of 81519552 is 25591518.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 176602 + ... + 177062.

It is an arithmetic number, because the mean of its divisors is an integer number (2796794).

Almost surely, 2^81519552 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 81519552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117465348).

81519552 is an abundant number, since it is smaller than the sum of its proper divisors (153411144).

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

81519552 is a wasteful number, since it uses less digits than its factorization.

81519552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 786 (or 773 counting only the distinct ones).

The product of its digits is 18000, while the sum is 36.

The square root of 81519552 is about 9028.8178628212. The cubic root of 81519552 is about 433.5979911219.

The spelling of 81519552 in words is "eighty-one million, five hundred nineteen thousand, five hundred fifty-two".