21290006 has 8 divisors (see below), whose sum is σ = 32102784. Its totient is φ = 10589080.

The previous prime is 21289999. The next prime is 21290021. The reversal of 21290006 is 60009212.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21290006.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27485 + ... + 28248.

It is an arithmetic number, because the mean of its divisors is an integer number (4012848).

Almost surely, 2^21290006 is an apocalyptic number.

21290006 is a deficient number, since it is larger than the sum of its proper divisors (10812778).

21290006 is a wasteful number, since it uses less digits than its factorization.

21290006 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55926.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 21290006 is about 4614.1094482034. The cubic root of 21290006 is about 277.1566231414.

Adding to 21290006 its reverse (60009212), we get a palindrome (81299218).

The spelling of 21290006 in words is "twenty-one million, two hundred ninety thousand, six".