6660607421 has 32 divisors (see below), whose sum is σ = 7716065280. Its totient is φ = 5701316544.

The previous prime is 6660607403. The next prime is 6660607423. The reversal of 6660607421 is 1247060666.

It is not a de Polignac number, because 6660607421 - 2¹⁰ = 6660606397 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 (6660607423) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1785260 + ... + 1788986.

It is an arithmetic number, because the mean of its divisors is an integer number (241127040).

Almost surely, 2^6660607421 is an apocalyptic number.

It is an amenable number.

6660607421 is a deficient number, since it is larger than the sum of its proper divisors (1055457859).

6660607421 is a wasteful number, since it uses less digits than its factorization.

6660607421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3945.

The product of its (nonzero) digits is 72576, while the sum is 38.

The square root of 6660607421 is about 81612.5445075694. The cubic root of 6660607421 is about 1881.5016880786.

The spelling of 6660607421 in words is "six billion, six hundred sixty million, six hundred seven thousand, four hundred twenty-one".