666509372458881 has 32 divisors (see below), whose sum is σ = 1043226900261888. Its totient is φ = 370517752025280.

The previous prime is 666509372458879. The next prime is 666509372458931. The reversal of 666509372458881 is 188854273905666.

666509372458881 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 666509372458881 - 2¹ = 666509372458879 is a prime.

It is a super-2 number, since 2×666509372458881² (a number of 30 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 666509372458797 and 666509372458806.

It is not an unprimeable number, because it can be changed into a prime (666509372450881) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 53587875 + ... + 64843496.

It is an arithmetic number, because the mean of its divisors is an integer number (32600840633184).

It is a 1-persistent number, because it is pandigital, but 2⋅666509372458881 = 1333018744917762 is not.

Almost surely, 2^{666509372458881} is an apocalyptic number.

It is an amenable number.

666509372458881 is a deficient number, since it is larger than the sum of its proper divisors (376717527803007).

666509372458881 is a wasteful number, since it uses less digits than its factorization.

666509372458881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118438661.

The product of its (nonzero) digits is 4180377600, while the sum is 78.

The spelling of 666509372458881 in words is "six hundred sixty-six trillion, five hundred nine billion, three hundred seventy-two million, four hundred fifty-eight thousand, eight hundred eighty-one".