74391063721 has 16 divisors (see below), whose sum is σ = 80615236240. Its totient is φ = 68645041920.

The previous prime is 74391063631. The next prime is 74391063727. The reversal of 74391063721 is 12736019347.

It can be written as a sum of positive squares in 8 ways, for example, as 37426771600 + 36964292121 = 193460^2 + 192261^2 .

It is not a de Polignac number, because 74391063721 - 2¹¹ = 74391061673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (74391063727) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12126571 + ... + 12132703.

It is an arithmetic number, because the mean of its divisors is an integer number (5038452265).

Almost surely, 2^74391063721 is an apocalyptic number.

It is an amenable number.

74391063721 is a deficient number, since it is larger than the sum of its proper divisors (6224172519).

74391063721 is an equidigital number, since it uses as much as digits as its factorization.

74391063721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11693 (or 11667 counting only the distinct ones).

The product of its (nonzero) digits is 190512, while the sum is 43.

The spelling of 74391063721 in words is "seventy-four billion, three hundred ninety-one million, sixty-three thousand, seven hundred twenty-one".