81636753 has 16 divisors (see below), whose sum is σ = 120519936. Its totient is φ = 48737040.

The previous prime is 81636721. The next prime is 81636761. The reversal of 81636753 is 35763618.

It is not a de Polignac number, because 81636753 - 2⁵ = 81636721 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81636713) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16251 + ... + 20672.

It is an arithmetic number, because the mean of its divisors is an integer number (7532496).

Almost surely, 2^81636753 is an apocalyptic number.

It is an amenable number.

81636753 is a deficient number, since it is larger than the sum of its proper divisors (38883183).

81636753 is a wasteful number, since it uses less digits than its factorization.

81636753 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37004.

The product of its digits is 90720, while the sum is 39.

The square root of 81636753 is about 9035.3059162377. The cubic root of 81636753 is about 433.8056868323.

The spelling of 81636753 in words is "eighty-one million, six hundred thirty-six thousand, seven hundred fifty-three".