661078503 has 20 divisors (see below), whose sum is σ = 1019396928. Its totient is φ = 426500640.

The previous prime is 661078501. The next prime is 661078513. The reversal of 661078503 is 305870166.

It is not a de Polignac number, because 661078503 - 2¹ = 661078501 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661078501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 129126 + ... + 134147.

Almost surely, 2^661078503 is an apocalyptic number.

661078503 is a deficient number, since it is larger than the sum of its proper divisors (358318425).

661078503 is a wasteful number, since it uses less digits than its factorization.

661078503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263316 (or 263307 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 661078503 is about 25711.4469254455. The cubic root of 661078503 is about 871.1327575426.

The spelling of 661078503 in words is "six hundred sixty-one million, seventy-eight thousand, five hundred three".