661011712 has 18 divisors (see below), whose sum is σ = 1319441858. Its totient is φ = 330505728.

The previous prime is 661011671. The next prime is 661011719. The reversal of 661011712 is 217110166.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 515471616 + 145540096 = 22704^2 + 12064^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661011719) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1290783 + ... + 1291294.

Almost surely, 2^661011712 is an apocalyptic number.

It is an amenable number.

661011712 is a deficient number, since it is larger than the sum of its proper divisors (658430146).

661011712 is an equidigital number, since it uses as much as digits as its factorization.

661011712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2582093 (or 2582079 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 25.

The square root of 661011712 is about 25710.1480353576. The cubic root of 661011712 is about 871.1034187236.

Adding to 661011712 its reverse (217110166), we get a palindrome (878121878).

The spelling of 661011712 in words is "six hundred sixty-one million, eleven thousand, seven hundred twelve".