21285426 has 8 divisors (see below), whose sum is σ = 42570864. Its totient is φ = 7095140.

The previous prime is 21285421. The next prime is 21285463. The reversal of 21285426 is 62458212.

It is a sphenic number, since it is the product of 3 distinct primes.

21285426 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 21285393 and 21285402.

It is not an unprimeable number, because it can be changed into a prime (21285421) 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, 1773780 + ... + 1773791.

It is an arithmetic number, because the mean of its divisors is an integer number (5321358).

Almost surely, 2^21285426 is an apocalyptic number.

21285426 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21285426 is a wasteful number, since it uses less digits than its factorization.

21285426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3547576.

The product of its digits is 7680, while the sum is 30.

The square root of 21285426 is about 4613.6131177202. The cubic root of 21285426 is about 277.1367473310.

The spelling of 21285426 in words is "twenty-one million, two hundred eighty-five thousand, four hundred twenty-six".