21606002 has 48 divisors (see below), whose sum is σ = 38814720. Its totient is φ = 8981280.

The previous prime is 21605999. The next prime is 21606007. The reversal of 21606002 is 20060612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21606007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 170063 + ... + 170189.

It is an arithmetic number, because the mean of its divisors is an integer number (808640).

Almost surely, 2^21606002 is an apocalyptic number.

21606002 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21606002 is a deficient number, since it is larger than the sum of its proper divisors (17208718).

21606002 is a wasteful number, since it uses less digits than its factorization.

21606002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207 (or 196 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 21606002 is about 4648.2256829892. The cubic root of 21606002 is about 278.5211228281.

Adding to 21606002 its reverse (20060612), we get a palindrome (41666614).

The spelling of 21606002 in words is "twenty-one million, six hundred six thousand, two".