212221987 has 4 divisors (see below), whose sum is σ = 212257456. Its totient is φ = 212186520.

The previous prime is 212221979. The next prime is 212221991. The reversal of 212221987 is 789122212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 212221987 - 2³ = 212221979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (212221927) 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, 6303 + ... + 21544.

It is an arithmetic number, because the mean of its divisors is an integer number (53064364).

Almost surely, 2^212221987 is an apocalyptic number.

212221987 is a deficient number, since it is larger than the sum of its proper divisors (35469).

212221987 is an equidigital number, since it uses as much as digits as its factorization.

212221987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35468.

The product of its digits is 8064, while the sum is 34.

The square root of 212221987 is about 14567.8408489385. The cubic root of 212221987 is about 596.4812440835.

The spelling of 212221987 in words is "two hundred twelve million, two hundred twenty-one thousand, nine hundred eighty-seven".