666556115503 has 4 divisors (see below), whose sum is σ = 666745643080. Its totient is φ = 666366587928.

The previous prime is 666556115501. The next prime is 666556115527. The reversal of 666556115503 is 305511655666.

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 666556115503 - 2¹ = 666556115501 is a prime.

It is a super-2 number, since 2×666556115503² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666556115501) 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, 94758513 + ... + 94765546.

It is an arithmetic number, because the mean of its divisors is an integer number (166686410770).

Almost surely, 2^666556115503 is an apocalyptic number.

666556115503 is a deficient number, since it is larger than the sum of its proper divisors (189527577).

666556115503 is a wasteful number, since it uses less digits than its factorization.

666556115503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189527576.

The product of its (nonzero) digits is 2430000, while the sum is 49.

The spelling of 666556115503 in words is "six hundred sixty-six billion, five hundred fifty-six million, one hundred fifteen thousand, five hundred three".