261443213 has 4 divisors (see below), whose sum is σ = 261576000. Its totient is φ = 261310428.

The previous prime is 261443201. The next prime is 261443239. The reversal of 261443213 is 312344162.

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 261443213 - 2¹² = 261439117 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261443263) 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, 63395 + ... + 67392.

It is an arithmetic number, because the mean of its divisors is an integer number (65394000).

Almost surely, 2^261443213 is an apocalyptic number.

It is an amenable number.

261443213 is a deficient number, since it is larger than the sum of its proper divisors (132787).

261443213 is a wasteful number, since it uses less digits than its factorization.

261443213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132786.

The product of its digits is 3456, while the sum is 26.

The square root of 261443213 is about 16169.2057009613. The cubic root of 261443213 is about 639.4291891291.

Adding to 261443213 its reverse (312344162), we get a palindrome (573787375).

The spelling of 261443213 in words is "two hundred sixty-one million, four hundred forty-three thousand, two hundred thirteen".