1668442547 has 4 divisors (see below), whose sum is σ = 1684035576. Its totient is φ = 1652849520.

The previous prime is 1668442493. The next prime is 1668442571. The reversal of 1668442547 is 7452448661.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1668442547 - 2⁶ = 1668442483 is a prime.

It is a super-3 number, since 3×1668442547³ (a number of 29 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1668442247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7796354 + ... + 7796567.

It is an arithmetic number, because the mean of its divisors is an integer number (421008894).

Almost surely, 2^1668442547 is an apocalyptic number.

1668442547 is a deficient number, since it is larger than the sum of its proper divisors (15593029).

1668442547 is a wasteful number, since it uses less digits than its factorization.

1668442547 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15593028.

The product of its digits is 1290240, while the sum is 47.

The square root of 1668442547 is about 40846.5732589651. The cubic root of 1668442547 is about 1186.0520598089.

The spelling of 1668442547 in words is "one billion, six hundred sixty-eight million, four hundred forty-two thousand, five hundred forty-seven".