261646127072605 has 64 divisors (see below), whose sum is σ = 360742923889920. Its totient is φ = 180174429388800.

The previous prime is 261646127072557. The next prime is 261646127072621. The reversal of 261646127072605 is 506270721646162.

It is not a de Polignac number, because 261646127072605 - 2⁹ = 261646127072093 is a prime.

It is a super-3 number, since 3×261646127072605³ (a number of 44 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (55).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 19466262685 + ... + 19466276125.

It is an arithmetic number, because the mean of its divisors is an integer number (5636608185780).

Almost surely, 2^{261646127072605} is an apocalyptic number.

It is an amenable number.

261646127072605 is a deficient number, since it is larger than the sum of its proper divisors (99096796817315).

261646127072605 is a wasteful number, since it uses less digits than its factorization.

261646127072605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22270.

The product of its (nonzero) digits is 10160640, while the sum is 55.

The spelling of 261646127072605 in words is "two hundred sixty-one trillion, six hundred forty-six billion, one hundred twenty-seven million, seventy-two thousand, six hundred five".