21112002020 has 24 divisors (see below), whose sum is σ = 44338471800. Its totient is φ = 8444178432.

The previous prime is 21112002017. The next prime is 21112002029. The reversal of 21112002020 is 2020021112.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3033586084 + 18078415936 = 55078^2 + 134456^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21112001992 and 21112002010.

It is not an unprimeable number, because it can be changed into a prime (21112002029) 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, 320036 + ... + 380324.

It is an arithmetic number, because the mean of its divisors is an integer number (1847436325).

Almost surely, 2^21112002020 is an apocalyptic number.

21112002020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21112002020 is an abundant number, since it is smaller than the sum of its proper divisors (23226469780).

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

21112002020 is a wasteful number, since it uses less digits than its factorization.

21112002020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77807 (or 77805 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21112002020 its reverse (2020021112), we get a palindrome (23132023132).

It can be divided in two parts, 211120020 and 20, that multiplied together give a square (4222400400 = 64980²).

The spelling of 21112002020 in words is "twenty-one billion, one hundred twelve million, two thousand, twenty".