81625653 has 48 divisors (see below), whose sum is σ = 134671680. Its totient is φ = 47319552.

The previous prime is 81625651. The next prime is 81625667. The reversal of 81625653 is 35652618.

It is not a de Polignac number, because 81625653 - 2¹ = 81625651 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81625651) 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 47 ways as a sum of consecutive naturals, for example, 124675 + ... + 125327.

It is an arithmetic number, because the mean of its divisors is an integer number (2805660).

Almost surely, 2^81625653 is an apocalyptic number.

It is an amenable number.

81625653 is a deficient number, since it is larger than the sum of its proper divisors (53046027).

81625653 is a wasteful number, since it uses less digits than its factorization.

81625653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 738 (or 735 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The square root of 81625653 is about 9034.6916383460. The cubic root of 81625653 is about 433.7860246858.

The spelling of 81625653 in words is "eighty-one million, six hundred twenty-five thousand, six hundred fifty-three".