6661554211 has 4 divisors (see below), whose sum is σ = 7173981472. Its totient is φ = 6149126952.

The previous prime is 6661554199. The next prime is 6661554233. The reversal of 6661554211 is 1124551666.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 6661554211 - 2⁷ = 6661554083 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6661504211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 256213611 + ... + 256213636.

It is an arithmetic number, because the mean of its divisors is an integer number (1793495368).

Almost surely, 2^6661554211 is an apocalyptic number.

6661554211 is a deficient number, since it is larger than the sum of its proper divisors (512427261).

6661554211 is a wasteful number, since it uses less digits than its factorization.

6661554211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 512427260.

The product of its digits is 43200, while the sum is 37.

The square root of 6661554211 is about 81618.3448190418. The cubic root of 6661554211 is about 1881.5908342315.

The spelling of 6661554211 in words is "six billion, six hundred sixty-one million, five hundred fifty-four thousand, two hundred eleven".