81386611 has 4 divisors (see below), whose sum is σ = 81632824. Its totient is φ = 81140400.

The previous prime is 81386609. The next prime is 81386651. The reversal of 81386611 is 11668318.

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

It is a cyclic number.

It is not a de Polignac number, because 81386611 - 2¹ = 81386609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81386651) 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, 122610 + ... + 123271.

It is an arithmetic number, because the mean of its divisors is an integer number (20408206).

Almost surely, 2^81386611 is an apocalyptic number.

81386611 is a deficient number, since it is larger than the sum of its proper divisors (246213).

81386611 is a wasteful number, since it uses less digits than its factorization.

81386611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246212.

The product of its digits is 6912, while the sum is 34.

The square root of 81386611 is about 9021.4528209153. The cubic root of 81386611 is about 433.3621609356.

The spelling of 81386611 in words is "eighty-one million, three hundred eighty-six thousand, six hundred eleven".