81848569 has 4 divisors (see below), whose sum is σ = 89289360. Its totient is φ = 74407780.

The previous prime is 81848563. The next prime is 81848581. The reversal of 81848569 is 96584818.

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 81848569 - 2⁹ = 81848057 is a prime.

It is a super-2 number, since 2×81848569² = 13398376494695522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81848563) 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, 3720379 + ... + 3720400.

It is an arithmetic number, because the mean of its divisors is an integer number (22322340).

Almost surely, 2^81848569 is an apocalyptic number.

It is an amenable number.

81848569 is a deficient number, since it is larger than the sum of its proper divisors (7440791).

81848569 is a wasteful number, since it uses less digits than its factorization.

81848569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7440790.

The product of its digits is 552960, while the sum is 49.

The square root of 81848569 is about 9047.0198960763. The cubic root of 81848569 is about 434.1805491578.

The spelling of 81848569 in words is "eighty-one million, eight hundred forty-eight thousand, five hundred sixty-nine".