202120001020 has 96 divisors (see below), whose sum is σ = 506499840000. Its totient is φ = 67686599232.

The previous prime is 202120001009. The next prime is 202120001051. The reversal of 202120001020 is 20100021202.

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 = 202120000988 and 202120001006.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 47620 + ... + 637579.

It is an arithmetic number, because the mean of its divisors is an integer number (5276040000).

Almost surely, 2^202120001020 is an apocalyptic number.

202120001020 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 202120001020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (253249920000).

202120001020 is an abundant number, since it is smaller than the sum of its proper divisors (304379838980).

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

202120001020 is a wasteful number, since it uses less digits than its factorization.

202120001020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 685272 (or 685256 counting only the distinct ones).

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

Adding to 202120001020 its reverse (20100021202), we get a palindrome (222220022222).

The spelling of 202120001020 in words is "two hundred two billion, one hundred twenty million, one thousand, twenty".