20021002120 has 96 divisors (see below), whose sum is σ = 52991155800. Its totient is φ = 6787156992.

The previous prime is 20021002117. The next prime is 20021002159. The reversal of 20021002120 is 2120012002.

It can be written as a sum of positive squares in 4 ways, for example, as 18217980676 + 1803021444 = 134974^2 + 42462^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 20021002097 and 20021002106.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 117054 + ... + 231826.

Almost surely, 2^20021002120 is an apocalyptic number.

20021002120 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 20021002120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26495577900).

20021002120 is an abundant number, since it is smaller than the sum of its proper divisors (32970153680).

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

20021002120 is a wasteful number, since it uses less digits than its factorization.

20021002120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114887 (or 114876 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

Adding to 20021002120 its reverse (2120012002), we get a palindrome (22141014122).

The spelling of 20021002120 in words is "twenty billion, twenty-one million, two thousand, one hundred twenty".