81179272 has 8 divisors (see below), whose sum is σ = 152211150. Its totient is φ = 40589632.

The previous prime is 81179269. The next prime is 81179291. The reversal of 81179272 is 27297118.

It can be written as a sum of positive squares in only one way, i.e., 73856836 + 7322436 = 8594^2 + 2706^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5073697 + ... + 5073712.

Almost surely, 2^81179272 is an apocalyptic number.

It is an amenable number.

81179272 is a deficient number, since it is larger than the sum of its proper divisors (71031878).

81179272 is a wasteful number, since it uses less digits than its factorization.

81179272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10147415 (or 10147411 counting only the distinct ones).

The product of its digits is 14112, while the sum is 37.

The square root of 81179272 is about 9009.9540509372. The cubic root of 81179272 is about 432.9938395509.

The spelling of 81179272 in words is "eighty-one million, one hundred seventy-nine thousand, two hundred seventy-two".