666221501415 has 16 divisors (see below), whose sum is σ = 1065983486976. Its totient is φ = 355308439200.

The previous prime is 666221501399. The next prime is 666221501443. The reversal of 666221501415 is 514105122666.

It is not a de Polignac number, because 666221501415 - 2⁴ = 666221501399 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19551 + ... + 1154480.

It is an arithmetic number, because the mean of its divisors is an integer number (66623967936).

Almost surely, 2^666221501415 is an apocalyptic number.

666221501415 is a deficient number, since it is larger than the sum of its proper divisors (399761985561).

666221501415 is a wasteful number, since it uses less digits than its factorization.

666221501415 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1211870.

The product of its (nonzero) digits is 86400, while the sum is 39.

The spelling of 666221501415 in words is "six hundred sixty-six billion, two hundred twenty-one million, five hundred one thousand, four hundred fifteen".