81927897 has 4 divisors (see below), whose sum is σ = 109237200. Its totient is φ = 54618596.

The previous prime is 81927887. The next prime is 81927917. The reversal of 81927897 is 79872918.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81927897 - 2¹⁴ = 81911513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81927847) 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, 13654647 + ... + 13654652.

It is an arithmetic number, because the mean of its divisors is an integer number (27309300).

Almost surely, 2^81927897 is an apocalyptic number.

It is an amenable number.

81927897 is a deficient number, since it is larger than the sum of its proper divisors (27309303).

81927897 is a wasteful number, since it uses less digits than its factorization.

81927897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27309302.

The product of its digits is 508032, while the sum is 51.

The square root of 81927897 is about 9051.4030404131. The cubic root of 81927897 is about 434.3207737770.

The spelling of 81927897 in words is "eighty-one million, nine hundred twenty-seven thousand, eight hundred ninety-seven".