261369321 has 4 divisors (see below), whose sum is σ = 348492432. Its totient is φ = 174246212.

The previous prime is 261369299. The next prime is 261369331. The reversal of 261369321 is 123963162.

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 261369321 - 2⁵ = 261369289 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261369331) 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, 43561551 + ... + 43561556.

It is an arithmetic number, because the mean of its divisors is an integer number (87123108).

Almost surely, 2^261369321 is an apocalyptic number.

It is an amenable number.

261369321 is a deficient number, since it is larger than the sum of its proper divisors (87123111).

261369321 is an equidigital number, since it uses as much as digits as its factorization.

261369321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87123110.

The product of its digits is 11664, while the sum is 33.

The square root of 261369321 is about 16166.9205787621. The cubic root of 261369321 is about 639.3689425806.

The spelling of 261369321 in words is "two hundred sixty-one million, three hundred sixty-nine thousand, three hundred twenty-one".