72247681 has 4 divisors (see below), whose sum is σ = 78815664. Its totient is φ = 65679700.

The previous prime is 72247667. The next prime is 72247687. The reversal of 72247681 is 18674227.

72247681 is nontrivially palindromic in base 14.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 72247681 - 2⁵ = 72247649 is a prime.

It is a super-2 number, since 2×72247681² = 10439454819755522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 72247681.

It is not an unprimeable number, because it can be changed into a prime (72247687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3283975 + ... + 3283996.

It is an arithmetic number, because the mean of its divisors is an integer number (19703916).

Almost surely, 2^72247681 is an apocalyptic number.

It is an amenable number.

72247681 is a deficient number, since it is larger than the sum of its proper divisors (6567983).

72247681 is a wasteful number, since it uses less digits than its factorization.

72247681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6567982.

The product of its digits is 37632, while the sum is 37.

The square root of 72247681 is about 8499.8635871407. The cubic root of 72247681 is about 416.4932531344.

The spelling of 72247681 in words is "seventy-two million, two hundred forty-seven thousand, six hundred eighty-one".