6660606661961 has 4 divisors (see below), whose sum is σ = 7612121899392. Its totient is φ = 5709091424532.

The previous prime is 6660606661903. The next prime is 6660606661963. The reversal of 6660606661961 is 1691666060666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6660606661961 - 2³⁴ = 6643426792777 is a prime.

It is a super-2 number, since 2×6660606661961² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 6660606661961.

It is not an unprimeable number, because it can be changed into a prime (6660606661963) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 475757618705 + ... + 475757618718.

It is an arithmetic number, because the mean of its divisors is an integer number (1903030474848).

Almost surely, 2^{6660606661961} is an apocalyptic number.

It is an amenable number.

6660606661961 is a deficient number, since it is larger than the sum of its proper divisors (951515237431).

6660606661961 is an equidigital number, since it uses as much as digits as its factorization.

6660606661961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 951515237430.

The product of its (nonzero) digits is 15116544, while the sum is 59.

The spelling of 6660606661961 in words is "six trillion, six hundred sixty billion, six hundred six million, six hundred sixty-one thousand, nine hundred sixty-one".