20110121000 has 64 divisors (see below), whose sum is σ = 47173698000. Its totient is φ = 8024217600.

The previous prime is 20110120993. The next prime is 20110121023. The reversal of 20110121000 is 12101102.

It can be written as a sum of positive squares in 8 ways, for example, as 4945183684 + 15164937316 = 70322^2 + 123146^2 .

It is a Harshad number since it is a multiple of its sum of digits (8).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 384416 + ... + 433584.

Almost surely, 2^20110121000 is an apocalyptic number.

20110121000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20110121000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23586849000).

20110121000 is an abundant number, since it is smaller than the sum of its proper divisors (27063577000).

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

20110121000 is a wasteful number, since it uses less digits than its factorization.

20110121000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49599 (or 49585 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 8.

Adding to 20110121000 its reverse (12101102), we get a palindrome (20122222102).

The spelling of 20110121000 in words is "twenty billion, one hundred ten million, one hundred twenty-one thousand".