81654633 has 24 divisors (see below), whose sum is σ = 122720520. Its totient is φ = 52254720.

The previous prime is 81654631. The next prime is 81654649. The reversal of 81654633 is 33645618.

81654633 is a `hidden beast` number, since 8 + 16 + 5 + 4 + 633 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 13046544 + 68608089 = 3612^2 + 8283^2 .

It is not a de Polignac number, because 81654633 - 2¹ = 81654631 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81654631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 49563 + ... + 51183.

It is an arithmetic number, because the mean of its divisors is an integer number (5113355).

Almost surely, 2^81654633 is an apocalyptic number.

It is an amenable number.

81654633 is a deficient number, since it is larger than the sum of its proper divisors (41065887).

81654633 is a wasteful number, since it uses less digits than its factorization.

81654633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1849 (or 1846 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 81654633 is about 9036.2953138994. The cubic root of 81654633 is about 433.8373550830.

The spelling of 81654633 in words is "eighty-one million, six hundred fifty-four thousand, six hundred thirty-three".