661742212 has 6 divisors (see below), whose sum is σ = 1158048878. Its totient is φ = 330871104.

The previous prime is 661742189. The next prime is 661742219. The reversal of 661742212 is 212247166.

It can be written as a sum of positive squares in only one way, i.e., 658230336 + 3511876 = 25656^2 + 1874^2 .

It is not an unprimeable number, because it can be changed into a prime (661742219) 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, 82717773 + ... + 82717780.

Almost surely, 2^661742212 is an apocalyptic number.

It is an amenable number.

661742212 is a deficient number, since it is larger than the sum of its proper divisors (496306666).

661742212 is a wasteful number, since it uses less digits than its factorization.

661742212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165435557 (or 165435555 counting only the distinct ones).

The product of its digits is 8064, while the sum is 31.

The square root of 661742212 is about 25724.3505651746. The cubic root of 661742212 is about 871.4241930597.

Adding to 661742212 its reverse (212247166), we get a palindrome (873989378).

It can be divided in two parts, 66174 and 2212, that added together give a palindrome (68386).

The spelling of 661742212 in words is "six hundred sixty-one million, seven hundred forty-two thousand, two hundred twelve".