81651934 has 24 divisors (see below), whose sum is σ = 153436248. Its totient is φ = 32301360.

The previous prime is 81651841. The next prime is 81651943. The reversal of 81651934 is 43915618.

It is a junction number, because it is equal to n+sod(n) for n = 81651893 and 81651902.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 30772 + ... + 33319.

It is an arithmetic number, because the mean of its divisors is an integer number (6393177).

Almost surely, 2^81651934 is an apocalyptic number.

81651934 is a deficient number, since it is larger than the sum of its proper divisors (71784314).

81651934 is a wasteful number, since it uses less digits than its factorization.

81651934 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64120 (or 64113 counting only the distinct ones).

The product of its digits is 25920, while the sum is 37.

The square root of 81651934 is about 9036.1459704899. The cubic root of 81651934 is about 433.8325750320.

The spelling of 81651934 in words is "eighty-one million, six hundred fifty-one thousand, nine hundred thirty-four".