74983109807821 has 2 divisors, whose sum is σ = 74983109807822. Its totient is φ = 74983109807820.

The previous prime is 74983109807819. The next prime is 74983109807899. The reversal of 74983109807821 is 12870890138947.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59151265652196 + 15831844155625 = 7690986^2 + 3978925^2 .

It is a cyclic number.

It is not a de Polignac number, because 74983109807821 - 2¹ = 74983109807819 is a prime.

Together with 74983109807819, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (74983109808821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 37491554903910 + 37491554903911.

It is an arithmetic number, because the mean of its divisors is an integer number (37491554903911).

Almost surely, 2^{74983109807821} is an apocalyptic number.

It is an amenable number.

74983109807821 is a deficient number, since it is larger than the sum of its proper divisors (1).

74983109807821 is an equidigital number, since it uses as much as digits as its factorization.

74983109807821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48771072, while the sum is 67.

The spelling of 74983109807821 in words is "seventy-four trillion, nine hundred eighty-three billion, one hundred nine million, eight hundred seven thousand, eight hundred twenty-one".