21449629 has 2 divisors, whose sum is σ = 21449630. Its totient is φ = 21449628.

The previous prime is 21449621. The next prime is 21449633. The reversal of 21449629 is 92694412.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21141604 + 308025 = 4598^2 + 555^2 .

It is a cyclic number.

It is not a de Polignac number, because 21449629 - 2³ = 21449621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21449621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10724814 + 10724815.

It is an arithmetic number, because the mean of its divisors is an integer number (10724815).

Almost surely, 2^21449629 is an apocalyptic number.

It is an amenable number.

21449629 is a deficient number, since it is larger than the sum of its proper divisors (1).

21449629 is an equidigital number, since it uses as much as digits as its factorization.

21449629 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 37.

The square root of 21449629 is about 4631.3744180319. The cubic root of 21449629 is about 277.8475649308.

The spelling of 21449629 in words is "twenty-one million, four hundred forty-nine thousand, six hundred twenty-nine".