74979821261 has 2 divisors, whose sum is σ = 74979821262. Its totient is φ = 74979821260.

The previous prime is 74979821227. The next prime is 74979821263. The reversal of 74979821261 is 16212897947.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 72754812361 + 2225008900 = 269731^2 + 47170^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-74979821261 is a prime.

Together with 74979821263, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 74979821197 and 74979821206.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (74979821263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 37489910630 + 37489910631.

It is an arithmetic number, because the mean of its divisors is an integer number (37489910631).

Almost surely, 2^74979821261 is an apocalyptic number.

It is an amenable number.

74979821261 is a deficient number, since it is larger than the sum of its proper divisors (1).

74979821261 is an equidigital number, since it uses as much as digits as its factorization.

74979821261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3048192, while the sum is 56.

The spelling of 74979821261 in words is "seventy-four billion, nine hundred seventy-nine million, eight hundred twenty-one thousand, two hundred sixty-one".