661614513539 has 6 divisors (see below), whose sum is σ = 769633209684. Its totient is φ = 567098154420.

The previous prime is 661614513457. The next prime is 661614513551. The reversal of 661614513539 is 935315416166.

It is a de Polignac number, because none of the positive numbers 2^k-661614513539 is a prime.

It is a super-2 number, since 2×661614513539² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661614513589) 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 5 ways as a sum of consecutive naturals, for example, 6751168457 + ... + 6751168554.

It is an arithmetic number, because the mean of its divisors is an integer number (128272201614).

Almost surely, 2^661614513539 is an apocalyptic number.

661614513539 is a deficient number, since it is larger than the sum of its proper divisors (108018696145).

661614513539 is a wasteful number, since it uses less digits than its factorization.

661614513539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13502337025 (or 13502337018 counting only the distinct ones).

The product of its digits is 1749600, while the sum is 50.

The spelling of 661614513539 in words is "six hundred sixty-one billion, six hundred fourteen million, five hundred thirteen thousand, five hundred thirty-nine".