121211011987 has 12 divisors (see below), whose sum is σ = 132726920760. Its totient is φ = 110629915968.

The previous prime is 121211011973. The next prime is 121211012009. The reversal of 121211011987 is 789110112121.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-121211011987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121211011967) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4014313 + ... + 4044394.

It is an arithmetic number, because the mean of its divisors is an integer number (11060576730).

Almost surely, 2^121211011987 is an apocalyptic number.

121211011987 is a deficient number, since it is larger than the sum of its proper divisors (11515908773).

121211011987 is an equidigital number, since it uses as much as digits as its factorization.

121211011987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8058822 (or 8058809 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 34.

The spelling of 121211011987 in words is "one hundred twenty-one billion, two hundred eleven million, eleven thousand, nine hundred eighty-seven".