81266421 has 8 divisors (see below), whose sum is σ = 109020640. Its totient is φ = 53844912.

The previous prime is 81266417. The next prime is 81266441. The reversal of 81266421 is 12466218.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81266421 - 2² = 81266417 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 (81266441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 82606 + ... + 83583.

It is an arithmetic number, because the mean of its divisors is an integer number (13627580).

Almost surely, 2^81266421 is an apocalyptic number.

It is an amenable number.

81266421 is a deficient number, since it is larger than the sum of its proper divisors (27754219).

81266421 is a wasteful number, since it uses less digits than its factorization.

81266421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166355.

The product of its digits is 4608, while the sum is 30.

The square root of 81266421 is about 9014.7890158339. The cubic root of 81266421 is about 433.1487291918.

The spelling of 81266421 in words is "eighty-one million, two hundred sixty-six thousand, four hundred twenty-one".