81662919 has 16 divisors (see below), whose sum is σ = 117422592. Its totient is φ = 50184288.

The previous prime is 81662881. The next prime is 81662941. The reversal of 81662919 is 91926618.

It is not a de Polignac number, because 81662919 - 2¹¹ = 81660871 is a prime.

It is a super-2 number, since 2×81662919² = 13337664679201122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81662419) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50014 + ... + 51620.

It is an arithmetic number, because the mean of its divisors is an integer number (7338912).

Almost surely, 2^81662919 is an apocalyptic number.

81662919 is a deficient number, since it is larger than the sum of its proper divisors (35759673).

81662919 is a wasteful number, since it uses less digits than its factorization.

81662919 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2926.

The product of its digits is 46656, while the sum is 42.

The square root of 81662919 is about 9036.7537866205. The cubic root of 81662919 is about 433.8520293054.

The spelling of 81662919 in words is "eighty-one million, six hundred sixty-two thousand, nine hundred nineteen".