21001012222 has 4 divisors (see below), whose sum is σ = 31501518336. Its totient is φ = 10500506110.

The previous prime is 21001012199. The next prime is 21001012243. The reversal of 21001012222 is 22221010012.

It is a happy number.

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 polite number, since it can be written as a sum of consecutive naturals, namely, 5250253054 + ... + 5250253057.

It is an arithmetic number, because the mean of its divisors is an integer number (7875379584).

Almost surely, 2^21001012222 is an apocalyptic number.

21001012222 is a deficient number, since it is larger than the sum of its proper divisors (10500506114).

21001012222 is a wasteful number, since it uses less digits than its factorization.

21001012222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10500506113.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21001012222 its reverse (22221010012), we get a palindrome (43222022234).

The spelling of 21001012222 in words is "twenty-one billion, one million, twelve thousand, two hundred twenty-two".