74736691041821 has 2 divisors, whose sum is σ = 74736691041822. Its totient is φ = 74736691041820.

The previous prime is 74736691041809. The next prime is 74736691041823. The reversal of 74736691041821 is 12814019663747.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69217175138596 + 5519515903225 = 8319686^2 + 2349365^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-74736691041821 is a prime.

Together with 74736691041823, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (74736691041823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 37368345520910 + 37368345520911.

It is an arithmetic number, because the mean of its divisors is an integer number (37368345520911).

Almost surely, 2^{74736691041821} is an apocalyptic number.

It is an amenable number.

74736691041821 is a deficient number, since it is larger than the sum of its proper divisors (1).

74736691041821 is an equidigital number, since it uses as much as digits as its factorization.

74736691041821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12192768, while the sum is 59.

The spelling of 74736691041821 in words is "seventy-four trillion, seven hundred thirty-six billion, six hundred ninety-one million, forty-one thousand, eight hundred twenty-one".