666636621041505 has 32 divisors (see below), whose sum is σ = 1068461695860480. Its totient is φ = 354925529020160.

The previous prime is 666636621041429. The next prime is 666636621041519. The reversal of 666636621041505 is 505140126636666.

It is not a de Polignac number, because 666636621041505 - 2¹⁴ = 666636621025121 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17800351 + ... + 40621739.

It is an arithmetic number, because the mean of its divisors is an integer number (33389427995640).

Almost surely, 2^{666636621041505} is an apocalyptic number.

It is an amenable number.

666636621041505 is a deficient number, since it is larger than the sum of its proper divisors (401825074818975).

666636621041505 is a wasteful number, since it uses less digits than its factorization.

666636621041505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22824761.

The product of its (nonzero) digits is 27993600, while the sum is 57.

The spelling of 666636621041505 in words is "six hundred sixty-six trillion, six hundred thirty-six billion, six hundred twenty-one million, forty-one thousand, five hundred five".