81339552 has 120 divisors (see below), whose sum is σ = 273452256. Its totient is φ = 23234688.

The previous prime is 81339529. The next prime is 81339553. The reversal of 81339552 is 25593318.

It is a super-2 number, since 2×81339552² = 13232245439121408, which contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (81339553) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 15903 + ... + 20385.

Almost surely, 2^81339552 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 81339552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136726128).

81339552 is an abundant number, since it is smaller than the sum of its proper divisors (192112704).

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

81339552 is a wasteful number, since it uses less digits than its factorization.

81339552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4512 (or 4495 counting only the distinct ones).

The product of its digits is 32400, while the sum is 36.

The square root of 81339552 is about 9018.8442718566. The cubic root of 81339552 is about 433.2786192589.

The spelling of 81339552 in words is "eighty-one million, three hundred thirty-nine thousand, five hundred fifty-two".