666725542765623 has 64 divisors (see below), whose sum is σ = 1078232871260160. Its totient is φ = 403814873577600.

The previous prime is 666725542765621. The next prime is 666725542765637. The reversal of 666725542765623 is 326567245527666.

It is not a de Polignac number, because 666725542765623 - 2¹ = 666725542765621 is a prime.

It is a super-2 number, since 2×666725542765623² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666725542765621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 15301324065 + ... + 15301367637.

It is an arithmetic number, because the mean of its divisors is an integer number (16847388613440).

Almost surely, 2^{666725542765623} is an apocalyptic number.

666725542765623 is a deficient number, since it is larger than the sum of its proper divisors (411507328494537).

666725542765623 is a wasteful number, since it uses less digits than its factorization.

666725542765623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75717 (or 75711 counting only the distinct ones).

The product of its digits is 4572288000, while the sum is 72.

The spelling of 666725542765623 in words is "six hundred sixty-six trillion, seven hundred twenty-five billion, five hundred forty-two million, seven hundred sixty-five thousand, six hundred twenty-three".