72773681 has 4 divisors (see below), whose sum is σ = 73091700. Its totient is φ = 72455664.

The previous prime is 72773677. The next prime is 72773683. The reversal of 72773681 is 18637727.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 61152400 + 11621281 = 7820^2 + 3409^2 .

It is a cyclic number.

It is not a de Polignac number, because 72773681 - 2² = 72773677 is a prime.

It is a super-2 number, since 2×72773681² = 10592017292579522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72773683) 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, 158666 + ... + 159123.

It is an arithmetic number, because the mean of its divisors is an integer number (18272925).

Almost surely, 2^72773681 is an apocalyptic number.

It is an amenable number.

72773681 is a deficient number, since it is larger than the sum of its proper divisors (318019).

72773681 is a wasteful number, since it uses less digits than its factorization.

72773681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 318018.

The product of its digits is 98784, while the sum is 41.

The square root of 72773681 is about 8530.7491464701. The cubic root of 72773681 is about 417.5015712229.

The spelling of 72773681 in words is "seventy-two million, seven hundred seventy-three thousand, six hundred eighty-one".