75281681 has 2 divisors, whose sum is σ = 75281682. Its totient is φ = 75281680.

The previous prime is 75281659. The next prime is 75281683. The reversal of 75281681 is 18618257.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60528400 + 14753281 = 7780^2 + 3841^2 .

It is a cyclic number.

It is not a de Polignac number, because 75281681 - 2¹⁰ = 75280657 is a prime.

It is a super-2 number, since 2×75281681² = 11334662988371522, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 75281683, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (75281683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 37640840 + 37640841.

It is an arithmetic number, because the mean of its divisors is an integer number (37640841).

Almost surely, 2^75281681 is an apocalyptic number.

It is an amenable number.

75281681 is a deficient number, since it is larger than the sum of its proper divisors (1).

75281681 is an equidigital number, since it uses as much as digits as its factorization.

75281681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 26880, while the sum is 38.

The square root of 75281681 is about 8676.5016567739. The cubic root of 75281681 is about 422.2436263105.

The spelling of 75281681 in words is "seventy-five million, two hundred eighty-one thousand, six hundred eighty-one".