661042454263 has 8 divisors (see below), whose sum is σ = 663409644368. Its totient is φ = 658675485504.

The previous prime is 661042454221. The next prime is 661042454273. The reversal of 661042454263 is 362454240166.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661042454263 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 (661042454273) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8035045 + ... + 8116897.

It is an arithmetic number, because the mean of its divisors is an integer number (82926205546).

Almost surely, 2^661042454263 is an apocalyptic number.

661042454263 is a deficient number, since it is larger than the sum of its proper divisors (2367190105).

661042454263 is a wasteful number, since it uses less digits than its factorization.

661042454263 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110673.

The product of its (nonzero) digits is 829440, while the sum is 43.

The spelling of 661042454263 in words is "six hundred sixty-one billion, forty-two million, four hundred fifty-four thousand, two hundred sixty-three".