666155616511 has 16 divisors (see below), whose sum is σ = 837881526528. Its totient is φ = 514488643200.

The previous prime is 666155616481. The next prime is 666155616521. The reversal of 666155616511 is 115616551666.

It is not a de Polignac number, because 666155616511 - 2²¹ = 666153519359 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666155616521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38271705 + ... + 38289106.

It is an arithmetic number, because the mean of its divisors is an integer number (52367595408).

Almost surely, 2^666155616511 is an apocalyptic number.

666155616511 is a deficient number, since it is larger than the sum of its proper divisors (171725910017).

666155616511 is a wasteful number, since it uses less digits than its factorization.

666155616511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76560942.

The product of its digits is 972000, while the sum is 49.

The spelling of 666155616511 in words is "six hundred sixty-six billion, one hundred fifty-five million, six hundred sixteen thousand, five hundred eleven".