81261336 has 32 divisors (see below), whose sum is σ = 218781360. Its totient is φ = 25003392.

The previous prime is 81261329. The next prime is 81261379. The reversal of 81261336 is 63316218.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 129915 + ... + 130538.

Almost surely, 2^81261336 is an apocalyptic number.

It is an amenable number.

81261336 is an abundant number, since it is smaller than the sum of its proper divisors (137520024).

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

81261336 is a wasteful number, since it uses less digits than its factorization.

81261336 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260475 (or 260471 counting only the distinct ones).

The product of its digits is 5184, while the sum is 30.

The square root of 81261336 is about 9014.5069748711. The cubic root of 81261336 is about 433.1396946804.

The spelling of 81261336 in words is "eighty-one million, two hundred sixty-one thousand, three hundred thirty-six".