121221012120021 has 48 divisors (see below), whose sum is σ = 199652681779200. Its totient is φ = 70155732435360.

The previous prime is 121221012120011. The next prime is 121221012120163. The reversal of 121221012120021 is 120021210122121.

121221012120021 is a `hidden beast` number, since 1 + 212 + 210 + 1 + 21 + 200 + 21 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-121221012120021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 121221012119976 and 121221012120003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121221012120001) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 43074441 + ... + 45802286.

It is an arithmetic number, because the mean of its divisors is an integer number (4159430870400).

Almost surely, 2^{121221012120021} is an apocalyptic number.

121221012120021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121221012120021 is a deficient number, since it is larger than the sum of its proper divisors (78431669659179).

121221012120021 is a wasteful number, since it uses less digits than its factorization.

121221012120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88877366 (or 88877363 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 121221012120021 its reverse (120021210122121), we get a palindrome (241242222242142).

The spelling of 121221012120021 in words is "one hundred twenty-one trillion, two hundred twenty-one billion, twelve million, one hundred twenty thousand, twenty-one".