21060406 has 8 divisors (see below), whose sum is σ = 31717224. Its totient is φ = 10488000.

The previous prime is 21060401. The next prime is 21060421. The reversal of 21060406 is 60406012.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21060401) 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, 20475 + ... + 21478.

It is an arithmetic number, because the mean of its divisors is an integer number (3964653).

Almost surely, 2^21060406 is an apocalyptic number.

21060406 is a deficient number, since it is larger than the sum of its proper divisors (10656818).

21060406 is a wasteful number, since it uses less digits than its factorization.

21060406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42206.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 21060406 is about 4589.1617971041. The cubic root of 21060406 is about 276.1566970589.

Adding to 21060406 its reverse (60406012), we get a palindrome (81466418).

The spelling of 21060406 in words is "twenty-one million, sixty thousand, four hundred six".