21221022112 has 12 divisors (see below), whose sum is σ = 41778887346. Its totient is φ = 10610511040.

The previous prime is 21221022103. The next prime is 21221022113. The reversal of 21221022112 is 21122012212.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 17828658576 + 3392363536 = 133524^2 + 58244^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is not an unprimeable number, because it can be changed into a prime (21221022113) by changing a digit.

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 as a sum of consecutive naturals, namely, 331578439 + ... + 331578502.

Almost surely, 2^21221022112 is an apocalyptic number.

It is an amenable number.

21221022112 is a deficient number, since it is larger than the sum of its proper divisors (20557865234).

21221022112 is an equidigital number, since it uses as much as digits as its factorization.

21221022112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 663156951 (or 663156943 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21221022112 its reverse (21122012212), we get a palindrome (42343034324).

The spelling of 21221022112 in words is "twenty-one billion, two hundred twenty-one million, twenty-two thousand, one hundred twelve".