20111121210 has 64 divisors (see below), whose sum is σ = 51329376000. Its totient is φ = 5025426432.

The previous prime is 20111121209. The next prime is 20111121211. The reversal of 20111121210 is 1212111102.

It is an interprime number because it is at equal distance from previous prime (20111121209) and next prime (20111121211).

It is not an unprimeable number, because it can be changed into a prime (20111121211) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 30691 + ... + 202889.

It is an arithmetic number, because the mean of its divisors is an integer number (802021500).

Almost surely, 2^20111121210 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20111121210, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25664688000).

20111121210 is an abundant number, since it is smaller than the sum of its proper divisors (31218254790).

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

20111121210 is a wasteful number, since it uses less digits than its factorization.

20111121210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172455.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 20111121210 its reverse (1212111102), we get a palindrome (21323232312).

The spelling of 20111121210 in words is "twenty billion, one hundred eleven million, one hundred twenty-one thousand, two hundred ten".