661245312 has 256 divisors, whose sum is σ = 2193408000. Its totient is φ = 171859968.

The previous prime is 661245301. The next prime is 661245317. The reversal of 661245312 is 213542166.

It is a self number, because there is not a number n which added to its sum of digits gives 661245312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661245317) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4437814 + ... + 4437962.

It is an arithmetic number, because the mean of its divisors is an integer number (8568000).

Almost surely, 2^661245312 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661245312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1096704000).

661245312 is an abundant number, since it is smaller than the sum of its proper divisors (1532162688).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661245312 is a wasteful number, since it uses less digits than its factorization.

661245312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 313 (or 301 counting only the distinct ones).

The product of its digits is 8640, while the sum is 30.

The square root of 661245312 is about 25714.6905872888. The cubic root of 661245312 is about 871.2060219447.

Adding to 661245312 its reverse (213542166), we get a palindrome (874787478).

The spelling of 661245312 in words is "six hundred sixty-one million, two hundred forty-five thousand, three hundred twelve".