1261603 has 6 divisors (see below), whose sum is σ = 1467636. Its totient is φ = 1081332.

The previous prime is 1261571. The next prime is 1261627. The reversal of 1261603 is 3061621.

It is not a de Polignac number, because 1261603 - 2⁵ = 1261571 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1261643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12825 + ... + 12922.

It is an arithmetic number, because the mean of its divisors is an integer number (244606).

2^1261603 is an apocalyptic number.

1261603 is a deficient number, since it is larger than the sum of its proper divisors (206033).

1261603 is an equidigital number, since it uses as much as digits as its factorization.

1261603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25761 (or 25754 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 1261603 is about 1123.2110220257. The cubic root of 1261603 is about 108.0540139052.

The spelling of 1261603 in words is "one million, two hundred sixty-one thousand, six hundred three".