261671507 has 8 divisors (see below), whose sum is σ = 266205312. Its totient is φ = 257176000.

The previous prime is 261671491. The next prime is 261671521. The reversal of 261671507 is 705176162.

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 261671507 - 2⁴ = 261671491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261671537) 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, 4382 + ... + 23292.

It is an arithmetic number, because the mean of its divisors is an integer number (33275664).

Almost surely, 2^261671507 is an apocalyptic number.

261671507 is a deficient number, since it is larger than the sum of its proper divisors (4533805).

261671507 is a wasteful number, since it uses less digits than its factorization.

261671507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19149.

The product of its (nonzero) digits is 17640, while the sum is 35.

The square root of 261671507 is about 16176.2636909764. The cubic root of 261671507 is about 639.6152529613.

The spelling of 261671507 in words is "two hundred sixty-one million, six hundred seventy-one thousand, five hundred seven".