666503613 has 8 divisors (see below), whose sum is σ = 987412800. Its totient is φ = 444335724.

The previous prime is 666503597. The next prime is 666503623. The reversal of 666503613 is 316305666.

It is a happy number.

It is not a de Polignac number, because 666503613 - 2⁴ = 666503597 is a prime.

It is a super-2 number, since 2×666503613² = 888454132284107538, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666503623) 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 7 ways as a sum of consecutive naturals, for example, 12342633 + ... + 12342686.

It is an arithmetic number, because the mean of its divisors is an integer number (123426600).

Almost surely, 2^666503613 is an apocalyptic number.

It is an amenable number.

666503613 is a deficient number, since it is larger than the sum of its proper divisors (320909187).

666503613 is a wasteful number, since it uses less digits than its factorization.

666503613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24685328 (or 24685322 counting only the distinct ones).

The product of its (nonzero) digits is 58320, while the sum is 36.

The square root of 666503613 is about 25816.7312609478. The cubic root of 666503613 is about 873.5092386802.

The spelling of 666503613 in words is "six hundred sixty-six million, five hundred three thousand, six hundred thirteen".