21426584 has 8 divisors (see below), whose sum is σ = 40174860. Its totient is φ = 10713288.

The previous prime is 21426583. The next prime is 21426607. The reversal of 21426584 is 48562412.

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 21426584.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21426583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1339154 + ... + 1339169.

Almost surely, 2^21426584 is an apocalyptic number.

It is an amenable number.

21426584 is a deficient number, since it is larger than the sum of its proper divisors (18748276).

21426584 is a wasteful number, since it uses less digits than its factorization.

21426584 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2678329 (or 2678325 counting only the distinct ones).

The product of its digits is 15360, while the sum is 32.

The square root of 21426584 is about 4628.8858270647. The cubic root of 21426584 is about 277.7480248785.

Adding to 21426584 its reverse (48562412), we get a palindrome (69988996).

The spelling of 21426584 in words is "twenty-one million, four hundred twenty-six thousand, five hundred eighty-four".