21426906 has 8 divisors (see below), whose sum is σ = 42853824. Its totient is φ = 7142300.

The previous prime is 21426901. The next prime is 21426907. The reversal of 21426906 is 60962412.

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

21426906 is an admirable number.

It is a super-3 number, since 3×21426906³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not an unprimeable number, because it can be changed into a prime (21426901) 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, 1785570 + ... + 1785581.

It is an arithmetic number, because the mean of its divisors is an integer number (5356728).

Almost surely, 2^21426906 is an apocalyptic number.

21426906 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.

21426906 is a wasteful number, since it uses less digits than its factorization.

21426906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3571156.

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 21426906 is about 4628.9206085220. The cubic root of 21426906 is about 277.7494162095.

The spelling of 21426906 in words is "twenty-one million, four hundred twenty-six thousand, nine hundred six".