1666455613 has 4 divisors (see below), whose sum is σ = 1666614400. Its totient is φ = 1666296828.

The previous prime is 1666455611. The next prime is 1666455631. The reversal of 1666455613 is 3165546661.

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, and also an emirpimes, since its reverse is a distinct semiprime: 3165546661 = 19 ⋅166607719.

It is a cyclic number.

It is not a de Polignac number, because 1666455613 - 2¹ = 1666455611 is a prime.

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 1666455613.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666455611) 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, 62445 + ... + 85042.

It is an arithmetic number, because the mean of its divisors is an integer number (416653600).

Almost surely, 2^1666455613 is an apocalyptic number.

It is an amenable number.

1666455613 is a deficient number, since it is larger than the sum of its proper divisors (158787).

1666455613 is a wasteful number, since it uses less digits than its factorization.

1666455613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158786.

The product of its digits is 388800, while the sum is 43.

The square root of 1666455613 is about 40822.2440955908. The cubic root of 1666455613 is about 1185.5810530258.

The spelling of 1666455613 in words is "one billion, six hundred sixty-six million, four hundred fifty-five thousand, six hundred thirteen".