21120222012 has 12 divisors (see below), whose sum is σ = 49280518056. Its totient is φ = 7040074000.

The previous prime is 21120221987. The next prime is 21120222023. The reversal of 21120222012 is 21022202112.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 21120221982 and 21120222000.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 880009239 + ... + 880009262.

It is an arithmetic number, because the mean of its divisors is an integer number (4106709838).

Almost surely, 2^21120222012 is an apocalyptic number.

It is an amenable number.

21120222012 is an abundant number, since it is smaller than the sum of its proper divisors (28160296044).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21120222012 is a wasteful number, since it uses less digits than its factorization.

21120222012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1760018508 (or 1760018506 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21120222012 its reverse (21022202112), we get a palindrome (42142424124).

The spelling of 21120222012 in words is "twenty-one billion, one hundred twenty million, two hundred twenty-two thousand, twelve".