212121211987 has 2 divisors, whose sum is σ = 212121211988. Its totient is φ = 212121211986.

The previous prime is 212121211957. The next prime is 212121212021. The reversal of 212121211987 is 789112121212.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-212121211987 is a prime.

It is not a weakly prime, because it can be changed into another prime (212121211957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106060605993 + 106060605994.

It is an arithmetic number, because the mean of its divisors is an integer number (106060605994).

Almost surely, 2^212121211987 is an apocalyptic number.

212121211987 is a deficient number, since it is larger than the sum of its proper divisors (1).

212121211987 is an equidigital number, since it uses as much as digits as its factorization.

212121211987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8064, while the sum is 37.

The spelling of 212121211987 in words is "two hundred twelve billion, one hundred twenty-one million, two hundred eleven thousand, nine hundred eighty-seven".