21012111149 has 2 divisors, whose sum is σ = 21012111150. Its totient is φ = 21012111148.

The previous prime is 21012111097. The next prime is 21012111151. The reversal of 21012111149 is 94111121012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20019420100 + 992691049 = 141490^2 + 31507^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012111149 - 2²⁰ = 21011062573 is a prime.

Together with 21012111151, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21012191149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506055574 + 10506055575.

It is an arithmetic number, because the mean of its divisors is an integer number (10506055575).

Almost surely, 2^21012111149 is an apocalyptic number.

It is an amenable number.

21012111149 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012111149 is an equidigital number, since it uses as much as digits as its factorization.

21012111149 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 23.

The spelling of 21012111149 in words is "twenty-one billion, twelve million, one hundred eleven thousand, one hundred forty-nine".