81662871 has 8 divisors (see below), whose sum is σ = 108974080. Its totient is φ = 54396792.

The previous prime is 81662839. The next prime is 81662879. The reversal of 81662871 is 17826618.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81662871 - 2⁵ = 81662839 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 (81662879) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6805 + ... + 14478.

It is an arithmetic number, because the mean of its divisors is an integer number (13621760).

Almost surely, 2^81662871 is an apocalyptic number.

81662871 is a deficient number, since it is larger than the sum of its proper divisors (27311209).

81662871 is a wasteful number, since it uses less digits than its factorization.

81662871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22565.

The product of its digits is 32256, while the sum is 39.

The square root of 81662871 is about 9036.7511307992. The cubic root of 81662871 is about 433.8519443019.

The spelling of 81662871 in words is "eighty-one million, six hundred sixty-two thousand, eight hundred seventy-one".