21146554152149 has 2 divisors, whose sum is σ = 21146554152150. Its totient is φ = 21146554152148.

The previous prime is 21146554152079. The next prime is 21146554152211. The reversal of 21146554152149 is 94125145564112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11864063580625 + 9282490571524 = 3444425^2 + 3046718^2 .

It is a cyclic number.

It is not a de Polignac number, because 21146554152149 - 2⁴⁴ = 3554368107733 is a prime.

It is a super-2 number, since 2×21146554152149² (a number of 27 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21146554152097 and 21146554152106.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21146554152049) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10573277076074 + 10573277076075.

It is an arithmetic number, because the mean of its divisors is an integer number (10573277076075).

Almost surely, 2^{21146554152149} is an apocalyptic number.

It is an amenable number.

21146554152149 is a deficient number, since it is larger than the sum of its proper divisors (1).

21146554152149 is an equidigital number, since it uses as much as digits as its factorization.

21146554152149 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728000, while the sum is 50.

The spelling of 21146554152149 in words is "twenty-one trillion, one hundred forty-six billion, five hundred fifty-four million, one hundred fifty-two thousand, one hundred forty-nine".