21548497 has 4 divisors (see below), whose sum is σ = 21582756. Its totient is φ = 21514240.

The previous prime is 21548491. The next prime is 21548507. The reversal of 21548497 is 79484512.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11282881 + 10265616 = 3359^2 + 3204^2 .

It is a cyclic number.

It is not a de Polignac number, because 21548497 - 2¹⁹ = 21024209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21548491) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16168 + ... + 17449.

It is an arithmetic number, because the mean of its divisors is an integer number (5395689).

Almost surely, 2^21548497 is an apocalyptic number.

It is an amenable number.

21548497 is a deficient number, since it is larger than the sum of its proper divisors (34259).

21548497 is an equidigital number, since it uses as much as digits as its factorization.

21548497 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34258.

The product of its digits is 80640, while the sum is 40.

The square root of 21548497 is about 4642.0358680217. The cubic root of 21548497 is about 278.2738059398.

The spelling of 21548497 in words is "twenty-one million, five hundred forty-eight thousand, four hundred ninety-seven".