81107272 has 24 divisors (see below), whose sum is σ = 161552610. Its totient is φ = 38167040.

The previous prime is 81107267. The next prime is 81107281. The reversal of 81107272 is 27270118.

It can be written as a sum of positive squares in 3 ways, for example, as 80174116 + 933156 = 8954^2 + 966^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 81107272.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 15229 + ... + 19852.

Almost surely, 2^81107272 is an apocalyptic number.

It is an amenable number.

81107272 is a deficient number, since it is larger than the sum of its proper divisors (80445338).

81107272 is a wasteful number, since it uses less digits than its factorization.

81107272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35121 (or 35100 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 28.

The square root of 81107272 is about 9005.9575837331. The cubic root of 81107272 is about 432.8657905345.

The spelling of 81107272 in words is "eighty-one million, one hundred seven thousand, two hundred seventy-two".