21111021112 has 8 divisors (see below), whose sum is σ = 39583164600. Its totient is φ = 10555510552.

The previous prime is 21111021101. The next prime is 21111021131. The reversal of 21111021112 is 21112011112.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 21111021092 and 21111021101.

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, 1319438812 + ... + 1319438827.

It is an arithmetic number, because the mean of its divisors is an integer number (4947895575).

Almost surely, 2^21111021112 is an apocalyptic number.

It is an amenable number.

21111021112 is a deficient number, since it is larger than the sum of its proper divisors (18472143488).

21111021112 is a wasteful number, since it uses less digits than its factorization.

21111021112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2638877645 (or 2638877641 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21111021112 its reverse (21112011112), we get a palindrome (42223032224).

The spelling of 21111021112 in words is "twenty-one billion, one hundred eleven million, twenty-one thousand, one hundred twelve".