72100681 has 2 divisors, whose sum is σ = 72100682. Its totient is φ = 72100680.

The previous prime is 72100631. The next prime is 72100703. The reversal of 72100681 is 18600127.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 72097081 + 3600 = 8491^2 + 60^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-72100681 is a prime.

It is a super-2 number, since 2×72100681² = 10397016401327522, which contains 22 as substring.

It is equal to p_4234273 and since 72100681 and 4234273 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (72100631) 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, 36050340 + 36050341.

It is an arithmetic number, because the mean of its divisors is an integer number (36050341).

Almost surely, 2^72100681 is an apocalyptic number.

It is an amenable number.

72100681 is a deficient number, since it is larger than the sum of its proper divisors (1).

72100681 is an equidigital number, since it uses as much as digits as its factorization.

72100681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 672, while the sum is 25.

The square root of 72100681 is about 8491.2119865188. The cubic root of 72100681 is about 416.2105862575.

The spelling of 72100681 in words is "seventy-two million, one hundred thousand, six hundred eighty-one".