21653006 has 4 divisors (see below), whose sum is σ = 32479512. Its totient is φ = 10826502.

The previous prime is 21652997. The next prime is 21653011. The reversal of 21653006 is 60035612.

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

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5413250 + ... + 5413253.

It is an arithmetic number, because the mean of its divisors is an integer number (8119878).

Almost surely, 2^21653006 is an apocalyptic number.

21653006 is a deficient number, since it is larger than the sum of its proper divisors (10826506).

21653006 is a wasteful number, since it uses less digits than its factorization.

21653006 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10826505.

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 21653006 is about 4653.2790589003. The cubic root of 21653006 is about 278.7229513862.

Adding to 21653006 its reverse (60035612), we get a palindrome (81688618).

The spelling of 21653006 in words is "twenty-one million, six hundred fifty-three thousand, six".