202121001020020 has 24 divisors (see below), whose sum is σ = 424874770273800. Its totient is φ = 80768273144832.

The previous prime is 202121001020009. The next prime is 202121001020047. The reversal of 202121001020020 is 20020100121202.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 5425200590436 + 196695800429584 = 2329206^2 + 14024828^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5007933265 + ... + 5007973624.

It is an arithmetic number, because the mean of its divisors is an integer number (17703115428075).

Almost surely, 2^{202121001020020} is an apocalyptic number.

202121001020020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

202121001020020 is an abundant number, since it is smaller than the sum of its proper divisors (222753769253780).

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

202121001020020 is a wasteful number, since it uses less digits than its factorization.

202121001020020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10015907907 (or 10015907905 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 202121001020020 its reverse (20020100121202), we get a palindrome (222141101141222).

The spelling of 202121001020020 in words is "two hundred two trillion, one hundred twenty-one billion, one million, twenty thousand, twenty".