21022210209 has 64 divisors (see below), whose sum is σ = 37663008768. Its totient is φ = 10072857600.

The previous prime is 21022210193. The next prime is 21022210241. The reversal of 21022210209 is 90201222012.

It is a happy number.

It is not a de Polignac number, because 21022210209 - 2⁴ = 21022210193 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (21022212209) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 6734169 + ... + 6737289.

It is an arithmetic number, because the mean of its divisors is an integer number (588484512).

Almost surely, 2^21022210209 is an apocalyptic number.

It is an amenable number.

21022210209 is a deficient number, since it is larger than the sum of its proper divisors (16640798559).

21022210209 is a wasteful number, since it uses less digits than its factorization.

21022210209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5398.

The product of its (nonzero) digits is 288, while the sum is 21.

The spelling of 21022210209 in words is "twenty-one billion, twenty-two million, two hundred ten thousand, two hundred nine".