73661661779 has 2 divisors, whose sum is σ = 73661661780. Its totient is φ = 73661661778.

The previous prime is 73661661739. The next prime is 73661661791. The reversal of 73661661779 is 97716616637.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 73661661779 - 2¹² = 73661657683 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (73661661739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36830830889 + 36830830890.

It is an arithmetic number, because the mean of its divisors is an integer number (36830830890).

Almost surely, 2^73661661779 is an apocalyptic number.

73661661779 is a deficient number, since it is larger than the sum of its proper divisors (1).

73661661779 is an equidigital number, since it uses as much as digits as its factorization.

73661661779 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12002256, while the sum is 59.

The spelling of 73661661779 in words is "seventy-three billion, six hundred sixty-one million, six hundred sixty-one thousand, seven hundred seventy-nine".