1666554724409 has 4 divisors (see below), whose sum is σ = 1666559504016. Its totient is φ = 1666549944804.

The previous prime is 1666554724391. The next prime is 1666554724427. The reversal of 1666554724409 is 9044274556661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (1666554724391) and next prime (1666554724427).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1666554724409 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1666554624409) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1821779 + ... + 2579144.

It is an arithmetic number, because the mean of its divisors is an integer number (416639876004).

Almost surely, 2^{1666554724409} is an apocalyptic number.

It is an amenable number.

1666554724409 is a deficient number, since it is larger than the sum of its proper divisors (4779607).

1666554724409 is an equidigital number, since it uses as much as digits as its factorization.

1666554724409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4779606.

The product of its (nonzero) digits is 43545600, while the sum is 59.

The spelling of 1666554724409 in words is "one trillion, six hundred sixty-six billion, five hundred fifty-four million, seven hundred twenty-four thousand, four hundred nine".