661727131 has 8 divisors (see below), whose sum is σ = 716568944. Its totient is φ = 607448160.

The previous prime is 661727123. The next prime is 661727161. The reversal of 661727131 is 131727166.

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

It is a cyclic number.

It is not a de Polignac number, because 661727131 - 2³ = 661727123 is a prime.

It is a super-2 number, since 2×661727131² = 875765591802982322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (661727161) 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 7 ways as a sum of consecutive naturals, for example, 138261 + ... + 142966.

It is an arithmetic number, because the mean of its divisors is an integer number (89571118).

Almost surely, 2^661727131 is an apocalyptic number.

661727131 is a deficient number, since it is larger than the sum of its proper divisors (54841813).

661727131 is a wasteful number, since it uses less digits than its factorization.

661727131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 281421.

The product of its digits is 10584, while the sum is 34.

The square root of 661727131 is about 25724.0574365709. The cubic root of 661727131 is about 871.4175731364.

The spelling of 661727131 in words is "six hundred sixty-one million, seven hundred twenty-seven thousand, one hundred thirty-one".