21542006 has 4 divisors (see below), whose sum is σ = 32313012. Its totient is φ = 10771002.

The previous prime is 21541979. The next prime is 21542063. The reversal of 21542006 is 60024512.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5385500 + ... + 5385503.

It is an arithmetic number, because the mean of its divisors is an integer number (8078253).

Almost surely, 2^21542006 is an apocalyptic number.

21542006 is a deficient number, since it is larger than the sum of its proper divisors (10771006).

21542006 is a wasteful number, since it uses less digits than its factorization.

21542006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10771005.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 21542006 is about 4641.3366609200. The cubic root of 21542006 is about 278.2458618923.

Adding to 21542006 its reverse (60024512), we get a palindrome (81566518).

The spelling of 21542006 in words is "twenty-one million, five hundred forty-two thousand, six".