261538670 has 8 divisors (see below), whose sum is σ = 470769624. Its totient is φ = 104615464.

The previous prime is 261538643. The next prime is 261538699. The reversal of 261538670 is 76835162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13076924 + ... + 13076943.

It is an arithmetic number, because the mean of its divisors is an integer number (58846203).

Almost surely, 2^261538670 is an apocalyptic number.

261538670 is a deficient number, since it is larger than the sum of its proper divisors (209230954).

261538670 is a wasteful number, since it uses less digits than its factorization.

261538670 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26153874.

The product of its (nonzero) digits is 60480, while the sum is 38.

The square root of 261538670 is about 16172.1572463293. The cubic root of 261538670 is about 639.5070015207.

The spelling of 261538670 in words is "two hundred sixty-one million, five hundred thirty-eight thousand, six hundred seventy".