121200000100021 has 4 divisors (see below), whose sum is σ = 121291887895200. Its totient is φ = 121108112304844.

The previous prime is 121200000100007. The next prime is 121200000100051. The reversal of 121200000100021 is 120001000002121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121200000100021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121200000099980 and 121200000100007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121200000100051) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45943895611 + ... + 45943898248.

It is an arithmetic number, because the mean of its divisors is an integer number (30322971973800).

Almost surely, 2^{121200000100021} is an apocalyptic number.

It is an amenable number.

121200000100021 is a deficient number, since it is larger than the sum of its proper divisors (91887795179).

121200000100021 is an equidigital number, since it uses as much as digits as its factorization.

121200000100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91887795178.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 121200000100021 its reverse (120001000002121), we get a palindrome (241201000102142).

The spelling of 121200000100021 in words is "one hundred twenty-one trillion, two hundred billion, one hundred thousand, twenty-one".