73766717921 has 4 divisors (see below), whose sum is σ = 79441080852. Its totient is φ = 68092354992.

The previous prime is 73766717897. The next prime is 73766717993. The reversal of 73766717921 is 12971766737.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6108985600 + 67657732321 = 78160^2 + 260111^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-73766717921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (73766717221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2837181446 + ... + 2837181471.

It is an arithmetic number, because the mean of its divisors is an integer number (19860270213).

Almost surely, 2^73766717921 is an apocalyptic number.

It is an amenable number.

73766717921 is a deficient number, since it is larger than the sum of its proper divisors (5674362931).

73766717921 is a wasteful number, since it uses less digits than its factorization.

73766717921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5674362930.

The product of its digits is 4667544, while the sum is 56.

The spelling of 73766717921 in words is "seventy-three billion, seven hundred sixty-six million, seven hundred seventeen thousand, nine hundred twenty-one".