665880405732555 has 16 divisors (see below), whose sum is σ = 1147363160647200. Its totient is φ = 327818045899008.

The previous prime is 665880405732551. The next prime is 665880405732587. The reversal of 665880405732555 is 555237504088566.

It is not a de Polignac number, because 665880405732555 - 2² = 665880405732551 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 665880405732555.

It is not an unprimeable number, because it can be changed into a prime (665880405732551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1707385655530 + ... + 1707385655919.

It is an arithmetic number, because the mean of its divisors is an integer number (71710197540450).

Almost surely, 2^{665880405732555} is an apocalyptic number.

665880405732555 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

665880405732555 is a deficient number, since it is larger than the sum of its proper divisors (481482754914645).

665880405732555 is a wasteful number, since it uses less digits than its factorization.

665880405732555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3414771311470.

The product of its (nonzero) digits is 1209600000, while the sum is 69.

The spelling of 665880405732555 in words is "six hundred sixty-five trillion, eight hundred eighty billion, four hundred five million, seven hundred thirty-two thousand, five hundred fifty-five".