121221021020 has 72 divisors (see below), whose sum is σ = 285763851072. Its totient is φ = 43142450560.

The previous prime is 121221021001. The next prime is 121221021113. The reversal of 121221021020 is 20120122121.

It is a junction number, because it is equal to n+sod(n) for n = 121221020986 and 121221021004.

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, 419147 + ... + 646626.

It is an arithmetic number, because the mean of its divisors is an integer number (3968942376).

Almost surely, 2^121221021020 is an apocalyptic number.

121221021020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121221021020 is an abundant number, since it is smaller than the sum of its proper divisors (164542830052).

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

121221021020 is a wasteful number, since it uses less digits than its factorization.

121221021020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1065851 (or 1065838 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 121221021020 its reverse (20120122121), we get a palindrome (141341143141).

The spelling of 121221021020 in words is "one hundred twenty-one billion, two hundred twenty-one million, twenty-one thousand, twenty".