73993781 has 2 divisors, whose sum is σ = 73993782. Its totient is φ = 73993780.

The previous prime is 73993757. The next prime is 73993789. The reversal of 73993781 is 18739937.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69872881 + 4120900 = 8359^2 + 2030^2 .

It is an emirp because it is prime and its reverse (18739937) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-73993781 is a prime.

It is a super-2 number, since 2×73993781² = 10950159253351922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (73993789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36996890 + 36996891.

It is an arithmetic number, because the mean of its divisors is an integer number (36996891).

Almost surely, 2^73993781 is an apocalyptic number.

It is an amenable number.

73993781 is a deficient number, since it is larger than the sum of its proper divisors (1).

73993781 is an equidigital number, since it uses as much as digits as its factorization.

73993781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 285768, while the sum is 47.

The square root of 73993781 is about 8601.9637874151. The cubic root of 73993781 is about 419.8218840359.

The spelling of 73993781 in words is "seventy-three million, nine hundred ninety-three thousand, seven hundred eighty-one".