1666412787525 has 24 divisors (see below), whose sum is σ = 2773381760064. Its totient is φ = 882867696000.

The previous prime is 1666412787503. The next prime is 1666412787563. The reversal of 1666412787525 is 5257872146661.

It is not a de Polignac number, because 1666412787525 - 2¹⁰ = 1666412786501 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 73560984 + ... + 73583633.

It is an arithmetic number, because the mean of its divisors is an integer number (115557573336).

Almost surely, 2^{1666412787525} is an apocalyptic number.

1666412787525 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1666412787525 is a deficient number, since it is larger than the sum of its proper divisors (1106968972539).

1666412787525 is a wasteful number, since it uses less digits than its factorization.

1666412787525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147144781 (or 147144776 counting only the distinct ones).

The product of its digits is 33868800, while the sum is 60.

The spelling of 1666412787525 in words is "one trillion, six hundred sixty-six billion, four hundred twelve million, seven hundred eighty-seven thousand, five hundred twenty-five".