81626673 has 16 divisors (see below), whose sum is σ = 115421760. Its totient is φ = 51134976.

The previous prime is 81626669. The next prime is 81626683. The reversal of 81626673 is 37662618.

It is not a de Polignac number, because 81626673 - 2² = 81626669 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81626653) 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 15 ways as a sum of consecutive naturals, for example, 55218 + ... + 56676.

It is an arithmetic number, because the mean of its divisors is an integer number (7213860).

Almost surely, 2^81626673 is an apocalyptic number.

It is an amenable number.

81626673 is a deficient number, since it is larger than the sum of its proper divisors (33795087).

81626673 is a wasteful number, since it uses less digits than its factorization.

81626673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2576.

The product of its digits is 72576, while the sum is 39.

The square root of 81626673 is about 9034.7480872463. The cubic root of 81626673 is about 433.7878315520.

The spelling of 81626673 in words is "eighty-one million, six hundred twenty-six thousand, six hundred seventy-three".