81942086 has 4 divisors (see below), whose sum is σ = 122913132. Its totient is φ = 40971042.

The previous prime is 81942073. The next prime is 81942089. The reversal of 81942086 is 68024918.

It is a semiprime because it is the product of two primes.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81942089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20485520 + ... + 20485523.

It is an arithmetic number, because the mean of its divisors is an integer number (30728283).

Almost surely, 2^81942086 is an apocalyptic number.

81942086 is a deficient number, since it is larger than the sum of its proper divisors (40971046).

81942086 is a wasteful number, since it uses less digits than its factorization.

81942086 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40971045.

The product of its (nonzero) digits is 27648, while the sum is 38.

The square root of 81942086 is about 9052.1868076173. The cubic root of 81942086 is about 434.3458455046.

The spelling of 81942086 in words is "eighty-one million, nine hundred forty-two thousand, eighty-six".