7891102122221 has 4 divisors (see below), whose sum is σ = 7979766191100. Its totient is φ = 7802438053344.

The previous prime is 7891102122193. The next prime is 7891102122269. The reversal of 7891102122221 is 1222212011987.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3051960084196 + 4839142038025 = 1746986^2 + 2199805^2 .

It is not a de Polignac number, because 7891102122221 - 2⁶ = 7891102122157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7891102122271) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44332034306 + ... + 44332034483.

It is an arithmetic number, because the mean of its divisors is an integer number (1994941547775).

Almost surely, 2^{7891102122221} is an apocalyptic number.

It is an amenable number.

7891102122221 is a deficient number, since it is larger than the sum of its proper divisors (88664068879).

7891102122221 is an equidigital number, since it uses as much as digits as its factorization.

7891102122221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88664068878.

The product of its (nonzero) digits is 16128, while the sum is 38.

The spelling of 7891102122221 in words is "seven trillion, eight hundred ninety-one billion, one hundred two million, one hundred twenty-two thousand, two hundred twenty-one".