213305987 has 6 divisors (see below), whose sum is σ = 226591788. Its totient is φ = 200758304.

The previous prime is 213305977. The next prime is 213305993. The reversal of 213305987 is 789503312.

213305987 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 213305987 - 2⁸ = 213305731 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 213305987.

It is not an unprimeable number, because it can be changed into a prime (213305977) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 368753 + ... + 369330.

It is an arithmetic number, because the mean of its divisors is an integer number (37765298).

Almost surely, 2^213305987 is an apocalyptic number.

213305987 is a deficient number, since it is larger than the sum of its proper divisors (13285801).

213305987 is an equidigital number, since it uses as much as digits as its factorization.

213305987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 738117 (or 738100 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 38.

The square root of 213305987 is about 14604.9986990756. The cubic root of 213305987 is about 597.4951005358.

Adding to 213305987 its sum of digits (38), we get a square (213306025 = 14605²).

The spelling of 213305987 in words is "two hundred thirteen million, three hundred five thousand, nine hundred eighty-seven".