81935945 has 64 divisors (see below), whose sum is σ = 129110016. Its totient is φ = 48522240.

The previous prime is 81935939. The next prime is 81935957. The reversal of 81935945 is 54953918.

It is a happy number.

It is not a de Polignac number, because 81935945 - 2¹⁰ = 81934921 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81935896 and 81935905.

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 521807 + ... + 521963.

It is an arithmetic number, because the mean of its divisors is an integer number (2017344).

Almost surely, 2^81935945 is an apocalyptic number.

It is an amenable number.

81935945 is a deficient number, since it is larger than the sum of its proper divisors (47174071).

81935945 is a wasteful number, since it uses less digits than its factorization.

81935945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 250.

The product of its digits is 194400, while the sum is 44.

The square root of 81935945 is about 9051.8476014568. The cubic root of 81935945 is about 434.3349948147.

The spelling of 81935945 in words is "eighty-one million, nine hundred thirty-five thousand, nine hundred forty-five".