6661903 has 4 divisors (see below), whose sum is σ = 6693688. Its totient is φ = 6630120.

The previous prime is 6661901. The next prime is 6661933. The reversal of 6661903 is 3091666.

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 6661903 - 2¹ = 6661901 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 (6661901) 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, 15576 + ... + 15997.

It is an arithmetic number, because the mean of its divisors is an integer number (1673422).

Almost surely, 2^6661903 is an apocalyptic number.

6661903 is a deficient number, since it is larger than the sum of its proper divisors (31785).

6661903 is a wasteful number, since it uses less digits than its factorization.

6661903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31784.

The product of its (nonzero) digits is 5832, while the sum is 31.

The square root of 6661903 is about 2581.0662525398. The cubic root of 6661903 is about 188.1623672751.

The spelling of 6661903 in words is "six million, six hundred sixty-one thousand, nine hundred three".