666436613 has 4 divisors (see below), whose sum is σ = 668579808. Its totient is φ = 664293420.

The previous prime is 666436607. The next prime is 666436721. The reversal of 666436613 is 316634666.

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.

It is a cyclic number.

It is not a de Polignac number, because 666436613 - 2⁶ = 666436549 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666436013) 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, 1071131 + ... + 1071752.

It is an arithmetic number, because the mean of its divisors is an integer number (167144952).

Almost surely, 2^666436613 is an apocalyptic number.

It is an amenable number.

666436613 is a deficient number, since it is larger than the sum of its proper divisors (2143195).

666436613 is a wasteful number, since it uses less digits than its factorization.

666436613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2143194.

The product of its digits is 279936, while the sum is 41.

The square root of 666436613 is about 25815.4336202203. The cubic root of 666436613 is about 873.4799679811.

The spelling of 666436613 in words is "six hundred sixty-six million, four hundred thirty-six thousand, six hundred thirteen".