661663365059 has 4 divisors (see below), whose sum is σ = 661852902600. Its totient is φ = 661473827520.

The previous prime is 661663365053. The next prime is 661663365061. The reversal of 661663365059 is 950563366166.

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

It is a cyclic number.

It is not a de Polignac number, because 661663365059 - 2⁴ = 661663365043 is a prime.

It is a super-2 number, since 2×661663365059² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 661663364995 and 661663365013.

It is not an unprimeable number, because it can be changed into a prime (661663365053) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 94763534 + ... + 94770515.

It is an arithmetic number, because the mean of its divisors is an integer number (165463225650).

Almost surely, 2^661663365059 is an apocalyptic number.

661663365059 is a deficient number, since it is larger than the sum of its proper divisors (189537541).

661663365059 is a wasteful number, since it uses less digits than its factorization.

661663365059 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189537540.

The product of its (nonzero) digits is 15746400, while the sum is 56.

The spelling of 661663365059 in words is "six hundred sixty-one billion, six hundred sixty-three million, three hundred sixty-five thousand, fifty-nine".