213180721 has 16 divisors (see below), whose sum is σ = 242282880. Its totient is φ = 186088320.

The previous prime is 213180719. The next prime is 213180733. The reversal of 213180721 is 127081312.

It is a happy number.

It is not a de Polignac number, because 213180721 - 2¹ = 213180719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (213183721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22606 + ... + 30616.

It is an arithmetic number, because the mean of its divisors is an integer number (15142680).

Almost surely, 2^213180721 is an apocalyptic number.

It is an amenable number.

213180721 is a deficient number, since it is larger than the sum of its proper divisors (29102159).

213180721 is a wasteful number, since it uses less digits than its factorization.

213180721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8136.

The product of its (nonzero) digits is 672, while the sum is 25.

The square root of 213180721 is about 14600.7096060431. The cubic root of 213180721 is about 597.3781160442.

The spelling of 213180721 in words is "two hundred thirteen million, one hundred eighty thousand, seven hundred twenty-one".