661512412 has 24 divisors (see below), whose sum is σ = 1265564160. Its totient is φ = 300050160.

The previous prime is 661512377. The next prime is 661512419. The reversal of 661512412 is 214215166.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661512419) 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, 5383 + ... + 36769.

It is an arithmetic number, because the mean of its divisors is an integer number (52731840).

Almost surely, 2^661512412 is an apocalyptic number.

It is an amenable number.

661512412 is a deficient number, since it is larger than the sum of its proper divisors (604051748).

661512412 is a wasteful number, since it uses less digits than its factorization.

661512412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31881 (or 31879 counting only the distinct ones).

The product of its digits is 2880, while the sum is 28.

The square root of 661512412 is about 25719.8835922716. The cubic root of 661512412 is about 871.3233096338.

Adding to 661512412 its reverse (214215166), we get a palindrome (875727578).

The spelling of 661512412 in words is "six hundred sixty-one million, five hundred twelve thousand, four hundred twelve".