73439981 has 2 divisors, whose sum is σ = 73439982. Its totient is φ = 73439980.

The previous prime is 73439957. The next prime is 73439999. The reversal of 73439981 is 18993437.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 37319881 + 36120100 = 6109^2 + 6010^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-73439981 is a prime.

It is a super-2 number, since 2×73439981² = 10786861618560722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (73439911) 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, 36719990 + 36719991.

It is an arithmetic number, because the mean of its divisors is an integer number (36719991).

Almost surely, 2^73439981 is an apocalyptic number.

It is an amenable number.

73439981 is a deficient number, since it is larger than the sum of its proper divisors (1).

73439981 is an equidigital number, since it uses as much as digits as its factorization.

73439981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 163296, while the sum is 44.

The square root of 73439981 is about 8569.7130056963. The cubic root of 73439981 is about 418.7718867004.

The spelling of 73439981 in words is "seventy-three million, four hundred thirty-nine thousand, nine hundred eighty-one".