6661599 has 12 divisors (see below), whose sum is σ = 10332504. Its totient is φ = 3806544.

The previous prime is 6661597. The next prime is 6661601. The reversal of 6661599 is 9951666.

It is an interprime number because it is at equal distance from previous prime (6661597) and next prime (6661601).

It is not a de Polignac number, because 6661599 - 2¹ = 6661597 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6661599.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6661597) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 22512 + ... + 22805.

It is an arithmetic number, because the mean of its divisors is an integer number (861042).

Almost surely, 2^6661599 is an apocalyptic number.

6661599 is a deficient number, since it is larger than the sum of its proper divisors (3670905).

6661599 is a wasteful number, since it uses less digits than its factorization.

6661599 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45334 (or 45327 counting only the distinct ones).

The product of its digits is 87480, while the sum is 42.

The square root of 6661599 is about 2581.0073614773. The cubic root of 6661599 is about 188.1595051185.

It can be divided in two parts, 6661 and 599, that added together give a triangular number (7260 = T₁₂₀).

The spelling of 6661599 in words is "six million, six hundred sixty-one thousand, five hundred ninety-nine".