261211263 has 4 divisors (see below), whose sum is σ = 348281688. Its totient is φ = 174140840.

The previous prime is 261211217. The next prime is 261211271. The reversal of 261211263 is 362112162.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 261211263 - 2⁶ = 261211199 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261211063) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43535208 + ... + 43535213.

It is an arithmetic number, because the mean of its divisors is an integer number (87070422).

Almost surely, 2^261211263 is an apocalyptic number.

261211263 is a deficient number, since it is larger than the sum of its proper divisors (87070425).

261211263 is an equidigital number, since it uses as much as digits as its factorization.

261211263 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87070424.

The product of its digits is 864, while the sum is 24.

The square root of 261211263 is about 16162.0315245330. The cubic root of 261211263 is about 639.2400346256.

The spelling of 261211263 in words is "two hundred sixty-one million, two hundred eleven thousand, two hundred sixty-three".