81925636 has 24 divisors (see below), whose sum is σ = 154693784. Its totient is φ = 37739520.

The previous prime is 81925631. The next prime is 81925639. The reversal of 81925636 is 63652918.

It can be written as a sum of positive squares in 4 ways, for example, as 2822400 + 79103236 = 1680^2 + 8894^2 .

It is not an unprimeable number, because it can be changed into a prime (81925631) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33826 + ... + 36166.

Almost surely, 2^81925636 is an apocalyptic number.

It is an amenable number.

81925636 is a deficient number, since it is larger than the sum of its proper divisors (72768148).

81925636 is a wasteful number, since it uses less digits than its factorization.

81925636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3031 (or 3029 counting only the distinct ones).

The product of its digits is 77760, while the sum is 40.

The square root of 81925636 is about 9051.2781417875. The cubic root of 81925636 is about 434.3167783602.

The spelling of 81925636 in words is "eighty-one million, nine hundred twenty-five thousand, six hundred thirty-six".