2121121220987 has 2 divisors, whose sum is σ = 2121121220988. Its totient is φ = 2121121220986.

The previous prime is 2121121220971. The next prime is 2121121221047. The reversal of 2121121220987 is 7890221211212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2121121220987 - 2⁴ = 2121121220971 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2121121220987.

It is not a weakly prime, because it can be changed into another prime (2121121220927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060560610493 + 1060560610494.

It is an arithmetic number, because the mean of its divisors is an integer number (1060560610494).

Almost surely, 2^{2121121220987} is an apocalyptic number.

2121121220987 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121121220987 is an equidigital number, since it uses as much as digits as its factorization.

2121121220987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16128, while the sum is 38.

The spelling of 2121121220987 in words is "two trillion, one hundred twenty-one billion, one hundred twenty-one million, two hundred twenty thousand, nine hundred eighty-seven".