21001212112 has 40 divisors (see below), whose sum is σ = 42625843200. Its totient is φ = 10010163072.

The previous prime is 21001212061. The next prime is 21001212143. The reversal of 21001212112 is 21121210012.

It is a junction number, because it is equal to n+sod(n) for n = 21001212092 and 21001212101.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 249808 + ... + 323119.

It is an arithmetic number, because the mean of its divisors is an integer number (1065646080).

Almost surely, 2^21001212112 is an apocalyptic number.

It is an amenable number.

21001212112 is an abundant number, since it is smaller than the sum of its proper divisors (21624631088).

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

21001212112 is a wasteful number, since it uses less digits than its factorization.

21001212112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 573043 (or 573037 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21001212112 its reverse (21121210012), we get a palindrome (42122422124).

The spelling of 21001212112 in words is "twenty-one billion, one million, two hundred twelve thousand, one hundred twelve".