21000021212222 has 32 divisors (see below), whose sum is σ = 33981419898720. Its totient is φ = 9675659635200.

The previous prime is 21000021212173. The next prime is 21000021212231. The reversal of 21000021212222 is 22221212000012.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21000021212222.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 515153213 + ... + 515193975.

It is an arithmetic number, because the mean of its divisors is an integer number (1061919371835).

Almost surely, 2^{21000021212222} is an apocalyptic number.

21000021212222 is a deficient number, since it is larger than the sum of its proper divisors (12981398686498).

21000021212222 is a wasteful number, since it uses less digits than its factorization.

21000021212222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74348.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21000021212222 its reverse (22221212000012), we get a palindrome (43221233212234).

The spelling of 21000021212222 in words is "twenty-one trillion, twenty-one million, two hundred twelve thousand, two hundred twenty-two".