21345150121 has 2 divisors, whose sum is σ = 21345150122. Its totient is φ = 21345150120.

The previous prime is 21345150103. The next prime is 21345150191. The reversal of 21345150121 is 12105154312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20125394496 + 1219755625 = 141864^2 + 34925^2 .

It is a cyclic number.

It is not a de Polignac number, because 21345150121 - 2¹¹ = 21345148073 is a prime.

It is not a weakly prime, because it can be changed into another prime (21345150191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10672575060 + 10672575061.

It is an arithmetic number, because the mean of its divisors is an integer number (10672575061).

Almost surely, 2^21345150121 is an apocalyptic number.

It is an amenable number.

21345150121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21345150121 is an equidigital number, since it uses as much as digits as its factorization.

21345150121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1200, while the sum is 25.

The spelling of 21345150121 in words is "twenty-one billion, three hundred forty-five million, one hundred fifty thousand, one hundred twenty-one".