661083660539 has 4 divisors (see below), whose sum is σ = 662162101056. Its totient is φ = 660005220024.

The previous prime is 661083660529. The next prime is 661083660541. The reversal of 661083660539 is 935066380166.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661083660539 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661083660529) 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, 539219339 + ... + 539220564.

It is an arithmetic number, because the mean of its divisors is an integer number (165540525264).

Almost surely, 2^661083660539 is an apocalyptic number.

661083660539 is a deficient number, since it is larger than the sum of its proper divisors (1078440517).

661083660539 is a wasteful number, since it uses less digits than its factorization.

661083660539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1078440516.

The product of its (nonzero) digits is 4199040, while the sum is 53.

The spelling of 661083660539 in words is "six hundred sixty-one billion, eighty-three million, six hundred sixty thousand, five hundred thirty-nine".