651603 has 4 divisors (see below), whose sum is σ = 868808. Its totient is φ = 434400.

The previous prime is 651587. The next prime is 651617. The reversal of 651603 is 306156.

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

It is not a de Polignac number, because 651603 - 2⁴ = 651587 is a prime.

It is a D-number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 651603.

It is not an unprimeable number, because it can be changed into a prime (651683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 108598 + ... + 108603.

It is an arithmetic number, because the mean of its divisors is an integer number (217202).

2⁶⁵¹⁶⁰³ is an apocalyptic number.

651603 is a deficient number, since it is larger than the sum of its proper divisors (217205).

651603 is a wasteful number, since it uses less digits than its factorization.

651603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 217204.

The product of its (nonzero) digits is 540, while the sum is 21.

The square root of 651603 is about 807.2193010576. The cubic root of 651603 is about 86.6950613732.

Adding to 651603 its reverse (306156), we get a palindrome (957759).

The spelling of 651603 in words is "six hundred fifty-one thousand, six hundred three".