21949453 has 2 divisors, whose sum is σ = 21949454. Its totient is φ = 21949452.

The previous prime is 21949409. The next prime is 21949463. The reversal of 21949453 is 35494912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11276164 + 10673289 = 3358^2 + 3267^2 .

It is a cyclic number.

It is not a de Polignac number, because 21949453 - 2¹³ = 21941261 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21949463) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10974726 + 10974727.

It is an arithmetic number, because the mean of its divisors is an integer number (10974727).

Almost surely, 2^21949453 is an apocalyptic number.

It is an amenable number.

21949453 is a deficient number, since it is larger than the sum of its proper divisors (1).

21949453 is an equidigital number, since it uses as much as digits as its factorization.

21949453 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 38880, while the sum is 37.

The square root of 21949453 is about 4685.0243329144. The cubic root of 21949453 is about 279.9891704995.

The spelling of 21949453 in words is "twenty-one million, nine hundred forty-nine thousand, four hundred fifty-three".