6661751407 has 4 divisors (see below), whose sum is σ = 6675431056. Its totient is φ = 6648071760.

The previous prime is 6661751389. The next prime is 6661751431. The reversal of 6661751407 is 7041571666.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6661751407 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 (6661751807) 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, 6839094 + ... + 6840067.

It is an arithmetic number, because the mean of its divisors is an integer number (1668857764).

Almost surely, 2^6661751407 is an apocalyptic number.

6661751407 is a deficient number, since it is larger than the sum of its proper divisors (13679649).

6661751407 is a wasteful number, since it uses less digits than its factorization.

6661751407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13679648.

The product of its (nonzero) digits is 211680, while the sum is 43.

The square root of 6661751407 is about 81619.5528473417. The cubic root of 6661751407 is about 1881.6094003956.

The spelling of 6661751407 in words is "six billion, six hundred sixty-one million, seven hundred fifty-one thousand, four hundred seven".