72267781 has 2 divisors, whose sum is σ = 72267782. Its totient is φ = 72267780.

The previous prime is 72267761. The next prime is 72267803. The reversal of 72267781 is 18776227.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39262756 + 33005025 = 6266^2 + 5745^2 .

It is a cyclic number.

It is not a de Polignac number, because 72267781 - 2⁵ = 72267749 is a prime.

It is a super-2 number, since 2×72267781² = 10445264341327922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72267751) 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 as a sum of consecutive naturals, namely, 36133890 + 36133891.

It is an arithmetic number, because the mean of its divisors is an integer number (36133891).

Almost surely, 2^72267781 is an apocalyptic number.

It is an amenable number.

72267781 is a deficient number, since it is larger than the sum of its proper divisors (1).

72267781 is an equidigital number, since it uses as much as digits as its factorization.

72267781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 65856, while the sum is 40.

The square root of 72267781 is about 8501.0458768319. The cubic root of 72267781 is about 416.5318736965.

The spelling of 72267781 in words is "seventy-two million, two hundred sixty-seven thousand, seven hundred eighty-one".