261527009 has 4 divisors (see below), whose sum is σ = 265210560. Its totient is φ = 257843460.

The previous prime is 261527003. The next prime is 261527011. The reversal of 261527009 is 900725162.

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 261527009 - 2²⁰ = 260478433 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261527003) 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, 1841669 + ... + 1841810.

It is an arithmetic number, because the mean of its divisors is an integer number (66302640).

Almost surely, 2^261527009 is an apocalyptic number.

It is an amenable number.

261527009 is a deficient number, since it is larger than the sum of its proper divisors (3683551).

261527009 is an equidigital number, since it uses as much as digits as its factorization.

261527009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3683550.

The product of its (nonzero) digits is 7560, while the sum is 32.

The square root of 261527009 is about 16171.7967152695. The cubic root of 261527009 is about 639.4974969963.

The spelling of 261527009 in words is "two hundred sixty-one million, five hundred twenty-seven thousand, nine".