81892993 has 16 divisors (see below), whose sum is σ = 101428096. Its totient is φ = 64385280.

The previous prime is 81892991. The next prime is 81892997. The reversal of 81892993 is 39929818.

It is a cyclic number.

It is not a de Polignac number, because 81892993 - 2¹ = 81892991 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81892991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12073 + ... + 17593.

It is an arithmetic number, because the mean of its divisors is an integer number (6339256).

Almost surely, 2^81892993 is an apocalyptic number.

It is an amenable number.

81892993 is a deficient number, since it is larger than the sum of its proper divisors (19535103).

81892993 is a wasteful number, since it uses less digits than its factorization.

81892993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5704.

The product of its digits is 279936, while the sum is 49.

The square root of 81892993 is about 9049.4747361380. The cubic root of 81892993 is about 434.2590866669.

The spelling of 81892993 in words is "eighty-one million, eight hundred ninety-two thousand, nine hundred ninety-three".