73909635661 has 2 divisors, whose sum is σ = 73909635662. Its totient is φ = 73909635660.

The previous prime is 73909635649. The next prime is 73909635689. The reversal of 73909635661 is 16653690937.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 70228180036 + 3681455625 = 265006^2 + 60675^2 .

It is a cyclic number.

It is not a de Polignac number, because 73909635661 - 2⁵ = 73909635629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (73909635601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36954817830 + 36954817831.

It is an arithmetic number, because the mean of its divisors is an integer number (36954817831).

Almost surely, 2^73909635661 is an apocalyptic number.

It is an amenable number.

73909635661 is a deficient number, since it is larger than the sum of its proper divisors (1).

73909635661 is an equidigital number, since it uses as much as digits as its factorization.

73909635661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5511240, while the sum is 55.

The spelling of 73909635661 in words is "seventy-three billion, nine hundred nine million, six hundred thirty-five thousand, six hundred sixty-one".