81860553 has 24 divisors (see below), whose sum is σ = 124151040. Its totient is φ = 51907680.

The previous prime is 81860551. The next prime is 81860557. The reversal of 81860553 is 35506818.

It is not a de Polignac number, because 81860553 - 2¹ = 81860551 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81860551) by changing a digit.

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, 13975 + ... + 18947.

It is an arithmetic number, because the mean of its divisors is an integer number (5172960).

Almost surely, 2^81860553 is an apocalyptic number.

It is an amenable number.

81860553 is a deficient number, since it is larger than the sum of its proper divisors (42290487).

81860553 is a wasteful number, since it uses less digits than its factorization.

81860553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5069 (or 5066 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 36.

The square root of 81860553 is about 9047.6821893787. The cubic root of 81860553 is about 434.2017385561.

The spelling of 81860553 in words is "eighty-one million, eight hundred sixty thousand, five hundred fifty-three".