661118473 has 2 divisors, whose sum is σ = 661118474. Its totient is φ = 661118472.

The previous prime is 661118467. The next prime is 661118483. The reversal of 661118473 is 374811166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 647040969 + 14077504 = 25437^2 + 3752^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661118473 is a prime.

It is not a weakly prime, because it can be changed into another prime (661118443) 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 as a sum of consecutive naturals, namely, 330559236 + 330559237.

It is an arithmetic number, because the mean of its divisors is an integer number (330559237).

Almost surely, 2^661118473 is an apocalyptic number.

It is an amenable number.

661118473 is a deficient number, since it is larger than the sum of its proper divisors (1).

661118473 is an equidigital number, since it uses as much as digits as its factorization.

661118473 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24192, while the sum is 37.

The square root of 661118473 is about 25712.2241939510. The cubic root of 661118473 is about 871.1503139420.

The spelling of 661118473 in words is "six hundred sixty-one million, one hundred eighteen thousand, four hundred seventy-three".