20151121000 has 80 divisors (see below), whose sum is σ = 47868071940. Its totient is φ = 7940143200.

The previous prime is 20151120959. The next prime is 20151121007. The reversal of 20151121000 is 12115102.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 2 ways, for example, as 13622157796 + 6528963204 = 116714^2 + 80802^2 .

It is not an unprimeable number, because it can be changed into a prime (20151121007) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 300762967 + ... + 300763033.

Almost surely, 2^20151121000 is an apocalyptic number.

20151121000 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 20151121000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23934035970).

20151121000 is an abundant number, since it is smaller than the sum of its proper divisors (27716950940).

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

20151121000 is an frugal number, since it uses more digits than its factorization.

20151121000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 289 (or 74 counting only the distinct ones).

The product of its (nonzero) digits is 20, while the sum is 13.

Adding to 20151121000 its reverse (12115102), we get a palindrome (20163236102).

The spelling of 20151121000 in words is "twenty billion, one hundred fifty-one million, one hundred twenty-one thousand".