261356213 has 4 divisors (see below), whose sum is σ = 265257120. Its totient is φ = 257455308.

The previous prime is 261356209. The next prime is 261356219. The reversal of 261356213 is 312653162.

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 261356213 - 2² = 261356209 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 (261356219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1950353 + ... + 1950486.

It is an arithmetic number, because the mean of its divisors is an integer number (66314280).

Almost surely, 2^261356213 is an apocalyptic number.

It is an amenable number.

261356213 is a deficient number, since it is larger than the sum of its proper divisors (3900907).

261356213 is an equidigital number, since it uses as much as digits as its factorization.

261356213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3900906.

The product of its digits is 6480, while the sum is 29.

The square root of 261356213 is about 16166.5151779844. The cubic root of 261356213 is about 639.3582540165.

The spelling of 261356213 in words is "two hundred sixty-one million, three hundred fifty-six thousand, two hundred thirteen".