1666533440709 has 32 divisors (see below), whose sum is σ = 2578161288960. Its totient is φ = 1061942422464.

The previous prime is 1666533440641. The next prime is 1666533440713. The reversal of 1666533440709 is 9070443356661.

It is not a de Polignac number, because 1666533440709 - 2¹² = 1666533436613 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666533440779) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 124654 + ... + 1829919.

It is an arithmetic number, because the mean of its divisors is an integer number (80567540280).

Almost surely, 2^{1666533440709} is an apocalyptic number.

It is an amenable number.

1666533440709 is a deficient number, since it is larger than the sum of its proper divisors (911627848251).

1666533440709 is a wasteful number, since it uses less digits than its factorization.

1666533440709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1955978 (or 1955972 counting only the distinct ones).

The product of its (nonzero) digits is 9797760, while the sum is 54.

The spelling of 1666533440709 in words is "one trillion, six hundred sixty-six billion, five hundred thirty-three million, four hundred forty thousand, seven hundred nine".