261223065 has 24 divisors (see below), whose sum is σ = 463320000. Its totient is φ = 136077984.

The previous prime is 261223063. The next prime is 261223069. The reversal of 261223065 is 560322162.

It is not a de Polignac number, because 261223065 - 2¹ = 261223063 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261223063) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 65565 + ... + 69434.

It is an arithmetic number, because the mean of its divisors is an integer number (19305000).

Almost surely, 2^261223065 is an apocalyptic number.

It is an amenable number.

261223065 is a deficient number, since it is larger than the sum of its proper divisors (202096935).

261223065 is a wasteful number, since it uses less digits than its factorization.

261223065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135053 (or 135050 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 261223065 is about 16162.3966354003. The cubic root of 261223065 is about 639.2496618231.

The spelling of 261223065 in words is "two hundred sixty-one million, two hundred twenty-three thousand, sixty-five".