81669927 has 4 divisors (see below), whose sum is σ = 108893240. Its totient is φ = 54446616.

The previous prime is 81669899. The next prime is 81669937. The reversal of 81669927 is 72996618.

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

It is not a de Polignac number, because 81669927 - 2¹⁵ = 81637159 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 (81669937) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13611652 + ... + 13611657.

It is an arithmetic number, because the mean of its divisors is an integer number (27223310).

Almost surely, 2^81669927 is an apocalyptic number.

81669927 is a deficient number, since it is larger than the sum of its proper divisors (27223313).

81669927 is a wasteful number, since it uses less digits than its factorization.

81669927 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27223312.

The product of its digits is 326592, while the sum is 48.

The square root of 81669927 is about 9037.1415281603. The cubic root of 81669927 is about 433.8644394588.

The spelling of 81669927 in words is "eighty-one million, six hundred sixty-nine thousand, nine hundred twenty-seven".