1660561110551 has 16 divisors (see below), whose sum is σ = 1902775369728. Its totient is φ = 1419595632000.

The previous prime is 1660561110503. The next prime is 1660561110563. The reversal of 1660561110551 is 1550111650661.

It is a happy number.

It is not a de Polignac number, because 1660561110551 - 2²⁶ = 1660494001687 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1660561110581) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 22956026 + ... + 23028248.

It is an arithmetic number, because the mean of its divisors is an integer number (118923460608).

Almost surely, 2^{1660561110551} is an apocalyptic number.

1660561110551 is a deficient number, since it is larger than the sum of its proper divisors (242214259177).

1660561110551 is an equidigital number, since it uses as much as digits as its factorization.

1660561110551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80822.

The product of its (nonzero) digits is 27000, while the sum is 38.

The spelling of 1660561110551 in words is "one trillion, six hundred sixty billion, five hundred sixty-one million, one hundred ten thousand, five hundred fifty-one".