1666428734 has 4 divisors (see below), whose sum is σ = 2499643104. Its totient is φ = 833214366.

The previous prime is 1666428727. The next prime is 1666428737. The reversal of 1666428734 is 4378246661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 4378246661 = 151 ⋅28995011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666428737) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 416607182 + ... + 416607185.

It is an arithmetic number, because the mean of its divisors is an integer number (624910776).

Almost surely, 2^1666428734 is an apocalyptic number.

1666428734 is a deficient number, since it is larger than the sum of its proper divisors (833214370).

1666428734 is an equidigital number, since it uses as much as digits as its factorization.

1666428734 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 833214369.

The product of its digits is 1161216, while the sum is 47.

The square root of 1666428734 is about 40821.9148742437. The cubic root of 1666428734 is about 1185.5746787377.

The spelling of 1666428734 in words is "one billion, six hundred sixty-six million, four hundred twenty-eight thousand, seven hundred thirty-four".