81619678 has 16 divisors (see below), whose sum is σ = 140482944. Its totient is φ = 34839000.

The previous prime is 81619613. The next prime is 81619723. The reversal of 81619678 is 87691618.

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 7 ways as a sum of consecutive naturals, for example, 8100 + ... + 15127.

It is an arithmetic number, because the mean of its divisors is an integer number (8780184).

Almost surely, 2^81619678 is an apocalyptic number.

81619678 is a deficient number, since it is larger than the sum of its proper divisors (58863266).

81619678 is a wasteful number, since it uses less digits than its factorization.

81619678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23487.

The product of its digits is 145152, while the sum is 46.

The square root of 81619678 is about 9034.3609624588. The cubic root of 81619678 is about 433.7754400446.

The spelling of 81619678 in words is "eighty-one million, six hundred nineteen thousand, six hundred seventy-eight".