81935968 has 12 divisors (see below), whose sum is σ = 161311500. Its totient is φ = 40967968.

The previous prime is 81935963. The next prime is 81935977. The reversal of 81935968 is 86953918.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81935963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1280218 + ... + 1280281.

It is an arithmetic number, because the mean of its divisors is an integer number (13442625).

Almost surely, 2^81935968 is an apocalyptic number.

It is an amenable number.

81935968 is a deficient number, since it is larger than the sum of its proper divisors (79375532).

81935968 is a wasteful number, since it uses less digits than its factorization.

81935968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2560509 (or 2560501 counting only the distinct ones).

The product of its digits is 466560, while the sum is 49.

The square root of 81935968 is about 9051.8488719156. The cubic root of 81935968 is about 434.3350354550.

It can be divided in two parts, 8193 and 5968, that added together give a square (14161 = 119²).

The spelling of 81935968 in words is "eighty-one million, nine hundred thirty-five thousand, nine hundred sixty-eight".