21492549 has 12 divisors (see below), whose sum is σ = 33433036. Its totient is φ = 13226112.

The previous prime is 21492547. The next prime is 21492551. The reversal of 21492549 is 94529412.

21492549 is a `hidden beast` number, since 21 + 4 + 92 + 549 = 666.

It is an interprime number because it is at equal distance from previous prime (21492547) and next prime (21492551).

It can be written as a sum of positive squares in 2 ways, for example, as 1404225 + 20088324 = 1185^2 + 4482^2 .

It is not a de Polignac number, because 21492549 - 2¹ = 21492547 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21492547) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 91732 + ... + 91965.

Almost surely, 2^21492549 is an apocalyptic number.

It is an amenable number.

21492549 is a deficient number, since it is larger than the sum of its proper divisors (11940487).

21492549 is a wasteful number, since it uses less digits than its factorization.

21492549 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 183716 (or 183713 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 21492549 is about 4636.0057161311. The cubic root of 21492549 is about 278.0327627312.

The spelling of 21492549 in words is "twenty-one million, four hundred ninety-two thousand, five hundred forty-nine".