21202120121020 has 24 divisors (see below), whose sum is σ = 46059778195200. Its totient is φ = 8188405012032.

The previous prime is 21202120120969. The next prime is 21202120121047. The reversal of 21202120121020 is 2012102120212.

It is a happy number.

It is a super-2 number, since 2×21202120121020² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21202120120985 and 21202120121003.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18277689180 + ... + 18277690339.

It is an arithmetic number, because the mean of its divisors is an integer number (1919157424800).

Almost surely, 2^{21202120121020} is an apocalyptic number.

21202120121020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21202120121020 is an abundant number, since it is smaller than the sum of its proper divisors (24857658074180).

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

21202120121020 is a wasteful number, since it uses less digits than its factorization.

21202120121020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36555379557 (or 36555379555 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21202120121020 its reverse (2012102120212), we get a palindrome (23214222241232).

The spelling of 21202120121020 in words is "twenty-one trillion, two hundred two billion, one hundred twenty million, one hundred twenty-one thousand, twenty".