1210123201921 has 2 divisors, whose sum is σ = 1210123201922. Its totient is φ = 1210123201920.

The previous prime is 1210123201913. The next prime is 1210123201967. The reversal of 1210123201921 is 1291023210121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1171102730625 + 39020471296 = 1082175^2 + 197536^2 .

It is a cyclic number.

It is not a de Polignac number, because 1210123201921 - 2³ = 1210123201913 is a prime.

It is not a weakly prime, because it can be changed into another prime (1210123201981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605061600960 + 605061600961.

It is an arithmetic number, because the mean of its divisors is an integer number (605061600961).

Almost surely, 2^{1210123201921} is an apocalyptic number.

It is an amenable number.

1210123201921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1210123201921 is an equidigital number, since it uses as much as digits as its factorization.

1210123201921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 25.

The spelling of 1210123201921 in words is "one trillion, two hundred ten billion, one hundred twenty-three million, two hundred one thousand, nine hundred twenty-one".