261522689 has 8 divisors (see below), whose sum is σ = 267891360. Its totient is φ = 255167136.

The previous prime is 261522637. The next prime is 261522691. The reversal of 261522689 is 986225162.

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 261522689 - 2¹⁶ = 261457153 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261522619) 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, 45854 + ... + 51240.

It is an arithmetic number, because the mean of its divisors is an integer number (33486420).

Almost surely, 2^261522689 is an apocalyptic number.

It is an amenable number.

261522689 is a deficient number, since it is larger than the sum of its proper divisors (6368671).

261522689 is a wasteful number, since it uses less digits than its factorization.

261522689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6559.

The product of its digits is 103680, while the sum is 41.

The square root of 261522689 is about 16171.6631488539. The cubic root of 261522689 is about 639.4939758248.

The spelling of 261522689 in words is "two hundred sixty-one million, five hundred twenty-two thousand, six hundred eighty-nine".