81261276 has 24 divisors (see below), whose sum is σ = 190997520. Its totient is φ = 26888832.

The previous prime is 81261251. The next prime is 81261281. The reversal of 81261276 is 67216218.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23071 + ... + 26358.

It is an arithmetic number, because the mean of its divisors is an integer number (7958230).

Almost surely, 2^81261276 is an apocalyptic number.

It is an amenable number.

81261276 is an abundant number, since it is smaller than the sum of its proper divisors (109736244).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81261276 is a wasteful number, since it uses less digits than its factorization.

81261276 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49573 (or 49571 counting only the distinct ones).

The product of its digits is 8064, while the sum is 33.

The square root of 81261276 is about 9014.5036469015. The cubic root of 81261276 is about 433.1395880763.

The spelling of 81261276 in words is "eighty-one million, two hundred sixty-one thousand, two hundred seventy-six".