21544426 has 4 divisors (see below), whose sum is σ = 32316642. Its totient is φ = 10772212.

The previous prime is 21544421. The next prime is 21544427. The reversal of 21544426 is 62444512.

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

It can be written as a sum of positive squares in only one way, i.e., 19368801 + 2175625 = 4401^2 + 1475^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21544394 and 21544403.

It is not an unprimeable number, because it can be changed into a prime (21544421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5386105 + ... + 5386108.

Almost surely, 2^21544426 is an apocalyptic number.

21544426 is a deficient number, since it is larger than the sum of its proper divisors (10772216).

21544426 is a wasteful number, since it uses less digits than its factorization.

21544426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10772215.

The product of its digits is 7680, while the sum is 28.

The square root of 21544426 is about 4641.5973543598. The cubic root of 21544426 is about 278.2562807575.

Adding to 21544426 its reverse (62444512), we get a palindrome (83988938).

The spelling of 21544426 in words is "twenty-one million, five hundred forty-four thousand, four hundred twenty-six".