261320667 has 4 divisors (see below), whose sum is σ = 348427560. Its totient is φ = 174213776.

The previous prime is 261320629. The next prime is 261320681. The reversal of 261320667 is 766023162.

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 261320667 - 2⁷ = 261320539 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261320627) 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, 43553442 + ... + 43553447.

It is an arithmetic number, because the mean of its divisors is an integer number (87106890).

Almost surely, 2^261320667 is an apocalyptic number.

261320667 is a deficient number, since it is larger than the sum of its proper divisors (87106893).

261320667 is an equidigital number, since it uses as much as digits as its factorization.

261320667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87106892.

The product of its (nonzero) digits is 18144, while the sum is 33.

The square root of 261320667 is about 16165.4157694753. The cubic root of 261320667 is about 639.3292671935.

The spelling of 261320667 in words is "two hundred sixty-one million, three hundred twenty thousand, six hundred sixty-seven".