1666109859407 has 16 divisors (see below), whose sum is σ = 1922603867712. Its totient is φ = 1414256847360.

The previous prime is 1666109859397. The next prime is 1666109859409. The reversal of 1666109859407 is 7049589016661.

It is not a de Polignac number, because 1666109859407 - 2¹⁸ = 1666109597263 is a prime.

It is a super-2 number, since 2×1666109859407² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1666109859407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666109859409) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42413 + ... + 1825929.

It is an arithmetic number, because the mean of its divisors is an integer number (120162741732).

Almost surely, 2^{1666109859407} is an apocalyptic number.

1666109859407 is a deficient number, since it is larger than the sum of its proper divisors (256494008305).

1666109859407 is a wasteful number, since it uses less digits than its factorization.

1666109859407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1784818.

The product of its (nonzero) digits is 19595520, while the sum is 62.

The spelling of 1666109859407 in words is "one trillion, six hundred sixty-six billion, one hundred nine million, eight hundred fifty-nine thousand, four hundred seven".