211321987 has 2 divisors, whose sum is σ = 211321988. Its totient is φ = 211321986.

The previous prime is 211321931. The next prime is 211321991. The reversal of 211321987 is 789123112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211321987 is a prime.

It is not a weakly prime, because it can be changed into another prime (211321687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105660993 + 105660994.

It is an arithmetic number, because the mean of its divisors is an integer number (105660994).

Almost surely, 2^211321987 is an apocalyptic number.

211321987 is a deficient number, since it is larger than the sum of its proper divisors (1).

211321987 is an equidigital number, since it uses as much as digits as its factorization.

211321987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6048, while the sum is 34.

The square root of 211321987 is about 14536.9180708980. The cubic root of 211321987 is about 595.6368549996.

The spelling of 211321987 in words is "two hundred eleven million, three hundred twenty-one thousand, nine hundred eighty-seven".