81267911 has 4 divisors (see below), whose sum is σ = 81286872. Its totient is φ = 81248952.

The previous prime is 81267881. The next prime is 81267913. The reversal of 81267911 is 11976218.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81267911 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 (81267913) 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, 341 + ... + 12753.

It is an arithmetic number, because the mean of its divisors is an integer number (20321718).

Almost surely, 2^81267911 is an apocalyptic number.

81267911 is a deficient number, since it is larger than the sum of its proper divisors (18961).

81267911 is a wasteful number, since it uses less digits than its factorization.

81267911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18960.

The product of its digits is 6048, while the sum is 35.

The square root of 81267911 is about 9014.8716574336. The cubic root of 81267911 is about 433.1513764011.

The spelling of 81267911 in words is "eighty-one million, two hundred sixty-seven thousand, nine hundred eleven".