21534449 has 4 divisors (see below), whose sum is σ = 21636720. Its totient is φ = 21432180.

The previous prime is 21534437. The next prime is 21534451. The reversal of 21534449 is 94443512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21534449 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21534479) 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, 50819 + ... + 51240.

It is an arithmetic number, because the mean of its divisors is an integer number (5409180).

Almost surely, 2^21534449 is an apocalyptic number.

It is an amenable number.

21534449 is a deficient number, since it is larger than the sum of its proper divisors (102271).

21534449 is a wasteful number, since it uses less digits than its factorization.

21534449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102270.

The product of its digits is 17280, while the sum is 32.

The square root of 21534449 is about 4640.5224921338. The cubic root of 21534449 is about 278.2133215940.

The spelling of 21534449 in words is "twenty-one million, five hundred thirty-four thousand, four hundred forty-nine".