20020121661136 has 80 divisors (see below), whose sum is σ = 41053153858560. Its totient is φ = 9431526504960.

The previous prime is 20020121661049. The next prime is 20020121661143. The reversal of 20020121661136 is 63116612102002.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 20020121661098 and 20020121661107.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 287788470 + ... + 287858026.

It is an arithmetic number, because the mean of its divisors is an integer number (513164423232).

Almost surely, 2^{20020121661136} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20020121661136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20526576929280).

20020121661136 is an abundant number, since it is smaller than the sum of its proper divisors (21033032197424).

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

20020121661136 is a wasteful number, since it uses less digits than its factorization.

20020121661136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74732 (or 74726 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 31.

Adding to 20020121661136 its reverse (63116612102002), we get a palindrome (83136733763138).

The spelling of 20020121661136 in words is "twenty trillion, twenty billion, one hundred twenty-one million, six hundred sixty-one thousand, one hundred thirty-six".