121821056213 has 2 divisors, whose sum is σ = 121821056214. Its totient is φ = 121821056212.

The previous prime is 121821056113. The next prime is 121821056311. The reversal of 121821056213 is 312650128121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 120265384849 + 1555671364 = 346793^2 + 39442^2 .

It is a cyclic number.

It is not a de Polignac number, because 121821056213 - 2¹² = 121821052117 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 121821056213.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121821056113) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60910528106 + 60910528107.

It is an arithmetic number, because the mean of its divisors is an integer number (60910528107).

Almost surely, 2^121821056213 is an apocalyptic number.

It is an amenable number.

121821056213 is a deficient number, since it is larger than the sum of its proper divisors (1).

121821056213 is an equidigital number, since it uses as much as digits as its factorization.

121821056213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5760, while the sum is 32.

The spelling of 121821056213 in words is "one hundred twenty-one billion, eight hundred twenty-one million, fifty-six thousand, two hundred thirteen".