81932661 has 8 divisors (see below), whose sum is σ = 121381760. Its totient is φ = 54621756.

The previous prime is 81932633. The next prime is 81932663. The reversal of 81932661 is 16623918.

It is not a de Polignac number, because 81932661 - 2⁵ = 81932629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81932663) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 1517245 + ... + 1517298.

It is an arithmetic number, because the mean of its divisors is an integer number (15172720).

Almost surely, 2^81932661 is an apocalyptic number.

It is an amenable number.

81932661 is a deficient number, since it is larger than the sum of its proper divisors (39449099).

81932661 is a wasteful number, since it uses less digits than its factorization.

81932661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3034552 (or 3034546 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 81932661 is about 9051.6662002087. Note that the first 3 decimals coincide. The cubic root of 81932661 is about 434.3291920087.

The spelling of 81932661 in words is "eighty-one million, nine hundred thirty-two thousand, six hundred sixty-one".