121221100022020 has 24 divisors (see below), whose sum is σ = 256817091555864. Its totient is φ = 48059338768896.

The previous prime is 121221100021999. The next prime is 121221100022021. The reversal of 121221100022020 is 20220001122121.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 17093279897604 + 104127820124416 = 4134402^2 + 10204304^2 .

It is a junction number, because it is equal to n+sod(n) for n = 121221100021985 and 121221100022003.

It is not an unprimeable number, because it can be changed into a prime (121221100022021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26818825179 + ... + 26818829698.

It is an arithmetic number, because the mean of its divisors is an integer number (10700712148161).

Almost surely, 2^{121221100022020} is an apocalyptic number.

121221100022020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121221100022020 is an abundant number, since it is smaller than the sum of its proper divisors (135595991533844).

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

121221100022020 is a wasteful number, since it uses less digits than its factorization.

121221100022020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53637654999 (or 53637654997 counting only the distinct ones).

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

Adding to 121221100022020 its reverse (20220001122121), we get a palindrome (141441101144141).

The spelling of 121221100022020 in words is "one hundred twenty-one trillion, two hundred twenty-one billion, one hundred million, twenty-two thousand, twenty".