20101220020 has 60 divisors (see below), whose sum is σ = 49245176484. Its totient is φ = 6891830400.

The previous prime is 20101220011. The next prime is 20101220099. The reversal of 20101220020 is 2002210102.

It can be written as a sum of positive squares in 2 ways, for example, as 12613086864 + 7488133156 = 112308^2 + 86534^2 .

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 = 20101219979 and 20101220006.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 161281 + ... + 257320.

Almost surely, 2^20101220020 is an apocalyptic number.

20101220020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20101220020 is an abundant number, since it is smaller than the sum of its proper divisors (29143956464).

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

20101220020 is an equidigital number, since it uses as much as digits as its factorization.

20101220020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 418638 (or 418615 counting only the distinct ones).

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

Adding to 20101220020 its reverse (2002210102), we get a palindrome (22103430122).

The spelling of 20101220020 in words is "twenty billion, one hundred one million, two hundred twenty thousand, twenty".