121321312020 has 72 divisors (see below), whose sum is σ = 368083237704. Its totient is φ = 32345733888.

The previous prime is 121321312003. The next prime is 121321312043. The reversal of 121321312020 is 20213123121.

121321312020 is a `hidden beast` number, since 12 + 1 + 321 + 312 + 0 + 20 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 8659046916 + 112662265104 = 93054^2 + 335652^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 121321311984 and 121321312002.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 847482 + ... + 980238.

Almost surely, 2^121321312020 is an apocalyptic number.

121321312020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121321312020 is an abundant number, since it is smaller than the sum of its proper divisors (246761925684).

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

121321312020 is a wasteful number, since it uses less digits than its factorization.

121321312020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137849 (or 137844 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 121321312020 its reverse (20213123121), we get a palindrome (141534435141).

The spelling of 121321312020 in words is "one hundred twenty-one billion, three hundred twenty-one million, three hundred twelve thousand, twenty".