261492065 has 4 divisors (see below), whose sum is σ = 313790484. Its totient is φ = 209193648.

The previous prime is 261492031. The next prime is 261492097. The reversal of 261492065 is 560294162.

It is a happy number.

261492065 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 560294162 = 2 ⋅280147081.

It can be written as a sum of positive squares in 2 ways, for example, as 156450064 + 105042001 = 12508^2 + 10249^2 .

It is a cyclic number.

It is not a de Polignac number, because 261492065 - 2⁶ = 261492001 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26149202 + ... + 26149211.

It is an arithmetic number, because the mean of its divisors is an integer number (78447621).

Almost surely, 2^261492065 is an apocalyptic number.

It is an amenable number.

261492065 is a deficient number, since it is larger than the sum of its proper divisors (52298419).

261492065 is an equidigital number, since it uses as much as digits as its factorization.

261492065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52298418.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 261492065 is about 16170.7162797447. The cubic root of 261492065 is about 639.4690135190.

The spelling of 261492065 in words is "two hundred sixty-one million, four hundred ninety-two thousand, sixty-five".