21111149 has 2 divisors, whose sum is σ = 21111150. Its totient is φ = 21111148.

The previous prime is 21111143. The next prime is 21111157. The reversal of 21111149 is 94111112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16080100 + 5031049 = 4010^2 + 2243^2 .

It is a cyclic number.

It is not a de Polignac number, because 21111149 - 2²⁴ = 4333933 is a prime.

It is a super-2 number, since 2×21111149² = 891361224200402, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21111149.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21111143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555574 + 10555575.

It is an arithmetic number, because the mean of its divisors is an integer number (10555575).

Almost surely, 2^21111149 is an apocalyptic number.

It is an amenable number.

21111149 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111149 is an equidigital number, since it uses as much as digits as its factorization.

21111149 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72, while the sum is 20.

The square root of 21111149 is about 4594.6870404849. The cubic root of 21111149 is about 276.3783100702.

The spelling of 21111149 in words is "twenty-one million, one hundred eleven thousand, one hundred forty-nine".