213720241 has 4 divisors (see below), whose sum is σ = 244251712. Its totient is φ = 183188772.

The previous prime is 213720217. The next prime is 213720263. The reversal of 213720241 is 142027312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 213720241 - 2¹⁵ = 213687473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (213720281) 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, 15265725 + ... + 15265738.

It is an arithmetic number, because the mean of its divisors is an integer number (61062928).

Almost surely, 2^213720241 is an apocalyptic number.

It is an amenable number.

213720241 is a deficient number, since it is larger than the sum of its proper divisors (30531471).

213720241 is an equidigital number, since it uses as much as digits as its factorization.

213720241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30531470.

The product of its (nonzero) digits is 672, while the sum is 22.

The square root of 213720241 is about 14619.1737454618. The cubic root of 213720241 is about 597.8816417696.

Adding to 213720241 its reverse (142027312), we get a palindrome (355747553).

The spelling of 213720241 in words is "two hundred thirteen million, seven hundred twenty thousand, two hundred forty-one".