74612421721 has 2 divisors, whose sum is σ = 74612421722. Its totient is φ = 74612421720.

The previous prime is 74612421679. The next prime is 74612421727. The reversal of 74612421721 is 12712421647.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 71757015625 + 2855406096 = 267875^2 + 53436^2 .

It is an emirp because it is prime and its reverse (12712421647) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-74612421721 is a prime.

It is not a weakly prime, because it can be changed into another prime (74612421727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 37306210860 + 37306210861.

It is an arithmetic number, because the mean of its divisors is an integer number (37306210861).

Almost surely, 2^74612421721 is an apocalyptic number.

It is an amenable number.

74612421721 is a deficient number, since it is larger than the sum of its proper divisors (1).

74612421721 is an equidigital number, since it uses as much as digits as its factorization.

74612421721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 37632, while the sum is 37.

The spelling of 74612421721 in words is "seventy-four billion, six hundred twelve million, four hundred twenty-one thousand, seven hundred twenty-one".