1261010432565 has 128 divisors (see below), whose sum is σ = 2545315315200. Its totient is φ = 587203706880.

The previous prime is 1261010432551. The next prime is 1261010432677. The reversal of 1261010432565 is 5652340101621.

1261010432565 is a `hidden beast` number, since 1 + 2 + 61 + 0 + 1 + 0 + 4 + 32 + 565 = 666.

It is not a de Polignac number, because 1261010432565 - 2¹⁷ = 1261010301493 is a prime.

It is a super-2 number, since 2×1261010432565² (a number of 25 digits) contains 22 as substring.

It is a Curzon number.

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 127 ways as a sum of consecutive naturals, for example, 21344647 + ... + 21403643.

It is an arithmetic number, because the mean of its divisors is an integer number (19885275900).

Almost surely, 2^{1261010432565} is an apocalyptic number.

1261010432565 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1261010432565 is an abundant number, since it is smaller than the sum of its proper divisors (1284304882635).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1261010432565 is a wasteful number, since it uses less digits than its factorization.

1261010432565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59684 (or 59678 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The spelling of 1261010432565 in words is "one trillion, two hundred sixty-one billion, ten million, four hundred thirty-two thousand, five hundred sixty-five".