73890349781 has 2 divisors, whose sum is σ = 73890349782. Its totient is φ = 73890349780.

The previous prime is 73890349777. The next prime is 73890349783. The reversal of 73890349781 is 18794309837.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 37921330756 + 35969019025 = 194734^2 + 189655^2 .

It is an emirp because it is prime and its reverse (18794309837) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 73890349781 - 2² = 73890349777 is a prime.

It is a super-2 number, since 2×73890349781² (a number of 23 digits) contains 22 as substring.

Together with 73890349783, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 73890349781.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (73890349783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36945174890 + 36945174891.

It is an arithmetic number, because the mean of its divisors is an integer number (36945174891).

Almost surely, 2^73890349781 is an apocalyptic number.

It is an amenable number.

73890349781 is a deficient number, since it is larger than the sum of its proper divisors (1).

73890349781 is an equidigital number, since it uses as much as digits as its factorization.

73890349781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9144576, while the sum is 59.

The spelling of 73890349781 in words is "seventy-three billion, eight hundred ninety million, three hundred forty-nine thousand, seven hundred eighty-one".