261536236652065 has 32 divisors (see below), whose sum is σ = 336078239870880. Its totient is φ = 194685849600000.

The previous prime is 261536236652059. The next prime is 261536236652071. The reversal of 261536236652065 is 560256632635162.

It is an interprime number because it is at equal distance from previous prime (261536236652059) and next prime (261536236652071).

It can be written as a sum of positive squares in 16 ways, for example, as 178820867801664 + 82715368850401 = 13372392^2 + 9094799^2 .

It is not a de Polignac number, because 261536236652065 - 2⁹ = 261536236651553 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 62276665 + ... + 66343465.

It is an arithmetic number, because the mean of its divisors is an integer number (10502444995965).

Almost surely, 2^{261536236652065} is an apocalyptic number.

It is an amenable number.

261536236652065 is a deficient number, since it is larger than the sum of its proper divisors (74542003218815).

261536236652065 is a wasteful number, since it uses less digits than its factorization.

261536236652065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4075413.

The product of its (nonzero) digits is 69984000, while the sum is 58.

The spelling of 261536236652065 in words is "two hundred sixty-one trillion, five hundred thirty-six billion, two hundred thirty-six million, six hundred fifty-two thousand, sixty-five".