213240261 has 16 divisors (see below), whose sum is σ = 306480384. Its totient is φ = 131100864.

The previous prime is 213240149. The next prime is 213240281. The reversal of 213240261 is 162042312.

It is not a de Polignac number, because 213240261 - 2⁹ = 213239749 is a prime.

It is a super-2 number, since 2×213240261² = 90942817822696242, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213240281) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 56155 + ... + 59831.

It is an arithmetic number, because the mean of its divisors is an integer number (19155024).

Almost surely, 2^213240261 is an apocalyptic number.

It is an amenable number.

213240261 is a deficient number, since it is larger than the sum of its proper divisors (93240123).

213240261 is a wasteful number, since it uses less digits than its factorization.

213240261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5180.

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 213240261 is about 14602.7484056940. The cubic root of 213240261 is about 597.4337254853.

Adding to 213240261 its reverse (162042312), we get a palindrome (375282573).

The spelling of 213240261 in words is "two hundred thirteen million, two hundred forty thousand, two hundred sixty-one".