661312652 has 192 divisors, whose sum is σ = 1669054464. Its totient is φ = 220872960.

The previous prime is 661312643. The next prime is 661312661. The reversal of 661312652 is 256213166.

661312652 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (661312643) and next prime (661312661).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3959873 + ... + 3960039.

It is an arithmetic number, because the mean of its divisors is an integer number (8692992).

Almost surely, 2^661312652 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 661312652, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (834527232).

661312652 is an abundant number, since it is smaller than the sum of its proper divisors (1007741812).

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

661312652 is a wasteful number, since it uses less digits than its factorization.

661312652 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 268 (or 266 counting only the distinct ones).

The product of its digits is 12960, while the sum is 32.

The square root of 661312652 is about 25715.9999222274. Note that the first 4 decimals coincide. The cubic root of 661312652 is about 871.2355949443.

It can be divided in two parts, 661 and 312652, that added together give a palindrome (313313).

The spelling of 661312652 in words is "six hundred sixty-one million, three hundred twelve thousand, six hundred fifty-two".