21626149 has 2 divisors, whose sum is σ = 21626150. Its totient is φ = 21626148.

The previous prime is 21626131. The next prime is 21626153. The reversal of 21626149 is 94162612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14577124 + 7049025 = 3818^2 + 2655^2 .

It is a cyclic number.

It is not a de Polignac number, because 21626149 - 2¹¹ = 21624101 is a prime.

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 21626149.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21626179) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10813074 + 10813075.

It is an arithmetic number, because the mean of its divisors is an integer number (10813075).

Almost surely, 2^21626149 is an apocalyptic number.

It is an amenable number.

21626149 is a deficient number, since it is larger than the sum of its proper divisors (1).

21626149 is an equidigital number, since it uses as much as digits as its factorization.

21626149 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5184, while the sum is 31.

The square root of 21626149 is about 4650.3923490389. The cubic root of 21626149 is about 278.6076670179.

The spelling of 21626149 in words is "twenty-one million, six hundred twenty-six thousand, one hundred forty-nine".