21210002066 has 32 divisors (see below), whose sum is σ = 35543743488. Its totient is φ = 9408929040.

The previous prime is 21210002059. The next prime is 21210002083. The reversal of 21210002066 is 66020001212.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1224035 + ... + 1241241.

It is an arithmetic number, because the mean of its divisors is an integer number (1110741984).

Almost surely, 2^21210002066 is an apocalyptic number.

21210002066 is a deficient number, since it is larger than the sum of its proper divisors (14333741422).

21210002066 is a wasteful number, since it uses less digits than its factorization.

21210002066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18566.

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 21210002066 its reverse (66020001212), we get a palindrome (87230003278).

The spelling of 21210002066 in words is "twenty-one billion, two hundred ten million, two thousand, sixty-six".