21111121210 has 16 divisors (see below), whose sum is σ = 39225825792. Its totient is φ = 8172046800.

The previous prime is 21111121183. The next prime is 21111121211. The reversal of 21111121210 is 1212111112.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21111121211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34049886 + ... + 34050505.

It is an arithmetic number, because the mean of its divisors is an integer number (2451614112).

Almost surely, 2^21111121210 is an apocalyptic number.

21111121210 is a deficient number, since it is larger than the sum of its proper divisors (18114704582).

21111121210 is a wasteful number, since it uses less digits than its factorization.

21111121210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68100429.

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

Adding to 21111121210 its reverse (1212111112), we get a palindrome (22323232322).

The spelling of 21111121210 in words is "twenty-one billion, one hundred eleven million, one hundred twenty-one thousand, two hundred ten".