72040681 has 2 divisors, whose sum is σ = 72040682. Its totient is φ = 72040680.

The previous prime is 72040673. The next prime is 72040687. The reversal of 72040681 is 18604027.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47389456 + 24651225 = 6884^2 + 4965^2 .

It is a cyclic number.

It is not a de Polignac number, because 72040681 - 2³ = 72040673 is a prime.

It is a super-2 number, since 2×72040681² = 10379719437887522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (72040687) by changing a digit.

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

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36020340 + 36020341.

It is an arithmetic number, because the mean of its divisors is an integer number (36020341).

Almost surely, 2^72040681 is an apocalyptic number.

It is an amenable number.

72040681 is a deficient number, since it is larger than the sum of its proper divisors (1).

72040681 is an equidigital number, since it uses as much as digits as its factorization.

72040681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 72040681 is about 8487.6781866421. The cubic root of 72040681 is about 416.0951016084.

The spelling of 72040681 in words is "seventy-two million, forty thousand, six hundred eighty-one".