661340012 has 12 divisors (see below), whose sum is σ = 1197253680. Its totient is φ = 319267536.

The previous prime is 661339981. The next prime is 661340033. The reversal of 661340012 is 210043166.

It is a happy number.

It is a super-2 number, since 2×661340012² = 874741222944320288, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 661340012.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2850488 + ... + 2850719.

It is an arithmetic number, because the mean of its divisors is an integer number (99771140).

Almost surely, 2^661340012 is an apocalyptic number.

It is an amenable number.

661340012 is a deficient number, since it is larger than the sum of its proper divisors (535913668).

661340012 is a wasteful number, since it uses less digits than its factorization.

661340012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5701240 (or 5701238 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 661340012 is about 25716.5318812627. The cubic root of 661340012 is about 871.2476097742.

Adding to 661340012 its reverse (210043166), we get a palindrome (871383178).

The spelling of 661340012 in words is "six hundred sixty-one million, three hundred forty thousand, twelve".