6660105155621 has 8 divisors (see below), whose sum is σ = 6754948027800. Its totient is φ = 6565796610048.

The previous prime is 6660105155593. The next prime is 6660105155623. The reversal of 6660105155621 is 1265515010666.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3254105719396 + 3405999436225 = 1803914^2 + 1845535^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6660105155621 - 2²⁶ = 6660038046757 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 (6660105155623) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 133556546 + ... + 133606403.

It is an arithmetic number, because the mean of its divisors is an integer number (844368503475).

Almost surely, 2^{6660105155621} is an apocalyptic number.

It is an amenable number.

6660105155621 is a deficient number, since it is larger than the sum of its proper divisors (94842872179).

6660105155621 is a wasteful number, since it uses less digits than its factorization.

6660105155621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 267163303.

The product of its (nonzero) digits is 324000, while the sum is 44.

The spelling of 6660105155621 in words is "six trillion, six hundred sixty billion, one hundred five million, one hundred fifty-five thousand, six hundred twenty-one".