661896360 has 320 divisors, whose sum is σ = 2406341520. Its totient is φ = 162570240.

The previous prime is 661896359. The next prime is 661896373. The reversal of 661896360 is 63698166.

661896360 is a `hidden beast` number, since 6 + 6 + 1 + 8 + 9 + 636 + 0 = 666.

661896360 is nontrivially palindromic in base 14.

It can be written as a sum of positive squares in 8 ways, for example, as 394181316 + 267715044 = 19854^2 + 16362^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

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 79 ways as a sum of consecutive naturals, for example, 3359782 + ... + 3359978.

Almost surely, 2^661896360 is an apocalyptic number.

661896360 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661896360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1203170760).

661896360 is an abundant number, since it is smaller than the sum of its proper divisors (1744445160).

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

661896360 is a wasteful number, since it uses less digits than its factorization.

661896360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 298 (or 285 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 45.

The square root of 661896360 is about 25727.3465402089. The cubic root of 661896360 is about 871.4918517669.

The spelling of 661896360 in words is "six hundred sixty-one million, eight hundred ninety-six thousand, three hundred sixty".