21449893 has 2 divisors, whose sum is σ = 21449894. Its totient is φ = 21449892.

The previous prime is 21449887. The next prime is 21449933. The reversal of 21449893 is 39894412.

It is an a-pointer prime, because the next prime (21449933) can be obtained adding 21449893 to its sum of digits (40).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13704804 + 7745089 = 3702^2 + 2783^2 .

It is a cyclic number.

It is not a de Polignac number, because 21449893 - 2¹⁷ = 21318821 is a prime.

It is a super-2 number, since 2×21449893² = 920195819422898, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21449093) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10724946 + 10724947.

It is an arithmetic number, because the mean of its divisors is an integer number (10724947).

Almost surely, 2^21449893 is an apocalyptic number.

It is an amenable number.

21449893 is a deficient number, since it is larger than the sum of its proper divisors (1).

21449893 is an equidigital number, since it uses as much as digits as its factorization.

21449893 is an evil number, because the sum of its binary digits is even.

The product of its digits is 62208, while the sum is 40.

The square root of 21449893 is about 4631.4029192028. The cubic root of 21449893 is about 277.8487048333.

The spelling of 21449893 in words is "twenty-one million, four hundred forty-nine thousand, eight hundred ninety-three".