1666624403 has 16 divisors (see below), whose sum is σ = 1749600000. Its totient is φ = 1585517472.

The previous prime is 1666624381. The next prime is 1666624423. The reversal of 1666624403 is 3044266661.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1666624403 - 2⁶ = 1666624339 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1666624423) 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 15 ways as a sum of consecutive naturals, for example, 616148 + ... + 618846.

It is an arithmetic number, because the mean of its divisors is an integer number (109350000).

Almost surely, 2^1666624403 is an apocalyptic number.

1666624403 is a deficient number, since it is larger than the sum of its proper divisors (82975597).

1666624403 is a wasteful number, since it uses less digits than its factorization.

1666624403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3034.

The product of its (nonzero) digits is 124416, while the sum is 38.

The square root of 1666624403 is about 40824.3114210148. The cubic root of 1666624403 is about 1185.6210795884.

The spelling of 1666624403 in words is "one billion, six hundred sixty-six million, six hundred twenty-four thousand, four hundred three".