666504031 has 4 divisors (see below), whose sum is σ = 667165600. Its totient is φ = 665842464.

The previous prime is 666504019. The next prime is 666504037. The reversal of 666504031 is 130405666.

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 666504031 - 2¹³ = 666495839 is a prime.

It is a super-2 number, since 2×666504031² = 888455246678497922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 666503984 and 666504002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666504037) 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, 329271 + ... + 331288.

It is an arithmetic number, because the mean of its divisors is an integer number (166791400).

Almost surely, 2^666504031 is an apocalyptic number.

666504031 is a deficient number, since it is larger than the sum of its proper divisors (661569).

666504031 is a wasteful number, since it uses less digits than its factorization.

666504031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 661568.

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 666504031 is about 25816.7393564718. The cubic root of 666504031 is about 873.5094212883.

Adding to 666504031 its reverse (130405666), we get a palindrome (796909697).

The spelling of 666504031 in words is "six hundred sixty-six million, five hundred four thousand, thirty-one".