261525667165 has 16 divisors (see below), whose sum is σ = 358709995008. Its totient is φ = 179308774656.

The previous prime is 261525667121. The next prime is 261525667201. The reversal of 261525667165 is 561766525162.

It is a cyclic number.

It is not a de Polignac number, because 261525667165 - 2¹⁷ = 261525536093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 203772 + ... + 751381.

It is an arithmetic number, because the mean of its divisors is an integer number (22419374688).

Almost surely, 2^261525667165 is an apocalyptic number.

It is an amenable number.

261525667165 is a deficient number, since it is larger than the sum of its proper divisors (97184327843).

261525667165 is an equidigital number, since it uses as much as digits as its factorization.

261525667165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 962988.

The product of its digits is 4536000, while the sum is 52.

The spelling of 261525667165 in words is "two hundred sixty-one billion, five hundred twenty-five million, six hundred sixty-seven thousand, one hundred sixty-five".