121321021020 has 24 divisors (see below), whose sum is σ = 339698859024. Its totient is φ = 32352272256.

The previous prime is 121321021009. The next prime is 121321021021. The reversal of 121321021020 is 20120123121.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121321021021) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 1011008449 + ... + 1011008568.

It is an arithmetic number, because the mean of its divisors is an integer number (14154119126).

Almost surely, 2^121321021020 is an apocalyptic number.

121321021020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121321021020 is an abundant number, since it is smaller than the sum of its proper divisors (218377838004).

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

121321021020 is a wasteful number, since it uses less digits than its factorization.

121321021020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2022017029 (or 2022017027 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 121321021020 its reverse (20120123121), we get a palindrome (141441144141).

The spelling of 121321021020 in words is "one hundred twenty-one billion, three hundred twenty-one million, twenty-one thousand, twenty".