661503700073 has 4 divisors (see below), whose sum is σ = 663944673408. Its totient is φ = 659062726740.

The previous prime is 661503700049. The next prime is 661503700111. The reversal of 661503700073 is 370007305166.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 661503700073 - 2⁸ = 661503699817 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (661503700573) 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 3 ways as a sum of consecutive naturals, for example, 1220486261 + ... + 1220486802.

It is an arithmetic number, because the mean of its divisors is an integer number (165986168352).

Almost surely, 2^661503700073 is an apocalyptic number.

It is an amenable number.

661503700073 is a deficient number, since it is larger than the sum of its proper divisors (2440973335).

661503700073 is a wasteful number, since it uses less digits than its factorization.

661503700073 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2440973334.

The product of its (nonzero) digits is 79380, while the sum is 38.

The spelling of 661503700073 in words is "six hundred sixty-one billion, five hundred three million, seven hundred thousand, seventy-three".