6665551 has 8 divisors (see below), whose sum is σ = 6804000. Its totient is φ = 6528480.

The previous prime is 6665539. The next prime is 6665567. The reversal of 6665551 is 1555666.

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 6665551 - 2¹³ = 6657359 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6665591) 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, 18925 + ... + 19273.

It is an arithmetic number, because the mean of its divisors is an integer number (850500).

Almost surely, 2^6665551 is an apocalyptic number.

6665551 is a deficient number, since it is larger than the sum of its proper divisors (138449).

6665551 is a wasteful number, since it uses less digits than its factorization.

6665551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 689.

The product of its digits is 27000, while the sum is 34.

The square root of 6665551 is about 2581.7728405110. The cubic root of 6665551 is about 188.1967063652.

The spelling of 6665551 in words is "six million, six hundred sixty-five thousand, five hundred fifty-one".