6665165561550 has 48 divisors (see below), whose sum is σ = 17399590104960. Its totient is φ = 1683831299040.

The previous prime is 6665165561491. The next prime is 6665165561573. The reversal of 6665165561550 is 551655615666.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1169324442 + ... + 1169330141.

It is an arithmetic number, because the mean of its divisors is an integer number (362491460520).

Almost surely, 2^{6665165561550} is an apocalyptic number.

6665165561550 is an abundant number, since it is smaller than the sum of its proper divisors (10734424543410).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6665165561550 is a wasteful number, since it uses less digits than its factorization.

6665165561550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2338654617 (or 2338654612 counting only the distinct ones).

The product of its (nonzero) digits is 24300000, while the sum is 57.

The spelling of 6665165561550 in words is "six trillion, six hundred sixty-five billion, one hundred sixty-five million, five hundred sixty-one thousand, five hundred fifty".