1661259551975 has 24 divisors (see below), whose sum is σ = 2085639010560. Its totient is φ = 1312454916320.

The previous prime is 1661259551957. The next prime is 1661259552011. The reversal of 1661259551975 is 5791559521661.

It is not a de Polignac number, because 1661259551975 - 2¹² = 1661259547879 is a prime.

It is a hoax number, since the sum of its digits (62) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4913936 + ... + 5241114.

It is an arithmetic number, because the mean of its divisors is an integer number (86901625440).

Almost surely, 2^{1661259551975} is an apocalyptic number.

1661259551975 is a deficient number, since it is larger than the sum of its proper divisors (424379458585).

1661259551975 is a wasteful number, since it uses less digits than its factorization.

1661259551975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 329719 (or 329714 counting only the distinct ones).

The product of its digits is 25515000, while the sum is 62.

The spelling of 1661259551975 in words is "one trillion, six hundred sixty-one billion, two hundred fifty-nine million, five hundred fifty-one thousand, nine hundred seventy-five".