81006552 has 96 divisors (see below), whose sum is σ = 249799680. Its totient is φ = 23474880.

The previous prime is 81006491. The next prime is 81006577. The reversal of 81006552 is 25560018.

81006552 is a `hidden beast` number, since 8 + 1 + 0 + 0 + 655 + 2 = 666.

It is a super-2 number, since 2×81006552² = 13124122933857408, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15993 + ... + 20439.

It is an arithmetic number, because the mean of its divisors is an integer number (2602080).

Almost surely, 2^81006552 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 81006552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124899840).

81006552 is an abundant number, since it is smaller than the sum of its proper divisors (168793128).

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

81006552 is a wasteful number, since it uses less digits than its factorization.

81006552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4493 (or 4486 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

The square root of 81006552 is about 9000.3639926394. The cubic root of 81006552 is about 432.6865369742.

The spelling of 81006552 in words is "eighty-one million, six thousand, five hundred fifty-two".