661831344 has 40 divisors (see below), whose sum is σ = 1899702320. Its totient is φ = 220610304.

The previous prime is 661831343. The next prime is 661831349. The reversal of 661831344 is 443138166.

It is a happy number.

661831344 is a `hidden beast` number, since 6 + 618 + 3 + 1 + 34 + 4 = 666.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 661831299 and 661831308.

It is not an unprimeable number, because it can be changed into a prime (661831343) 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, 765577 + ... + 766440.

It is an arithmetic number, because the mean of its divisors is an integer number (47492558).

Almost surely, 2^661831344 is an apocalyptic number.

It is an amenable number.

661831344 is an abundant number, since it is smaller than the sum of its proper divisors (1237870976).

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

661831344 is a wasteful number, since it uses less digits than its factorization.

661831344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1532034 (or 1532022 counting only the distinct ones).

The product of its digits is 41472, while the sum is 36.

The square root of 661831344 is about 25726.0829509663. The cubic root of 661831344 is about 871.4633161970.

The spelling of 661831344 in words is "six hundred sixty-one million, eight hundred thirty-one thousand, three hundred forty-four".