261697969 has 8 divisors (see below), whose sum is σ = 284620392. Its totient is φ = 239174400.

The previous prime is 261697897. The next prime is 261697973. The reversal of 261697969 is 969796162.

It can be written as a sum of positive squares in 4 ways, for example, as 82137969 + 179560000 = 9063^2 + 13400^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 261697969 - 2¹³ = 261689777 is a prime.

It is a super-2 number, since 2×261697969² = 136971653957449922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261637969) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 98344 + ... + 100969.

It is an arithmetic number, because the mean of its divisors is an integer number (35577549).

Almost surely, 2^261697969 is an apocalyptic number.

It is an amenable number.

261697969 is a deficient number, since it is larger than the sum of its proper divisors (22922423).

261697969 is a wasteful number, since it uses less digits than its factorization.

261697969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199427.

The product of its digits is 2204496, while the sum is 55.

The square root of 261697969 is about 16177.0815971238. The cubic root of 261697969 is about 639.6368129807.

The spelling of 261697969 in words is "two hundred sixty-one million, six hundred ninety-seven thousand, nine hundred sixty-nine".