661396160 has 112 divisors (see below), whose sum is σ = 1653917952. Its totient is φ = 251596800.

The previous prime is 661396121. The next prime is 661396181. The reversal of 661396160 is 61693166.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 604574 + ... + 605666.

Almost surely, 2^661396160 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 661396160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (826958976).

661396160 is an abundant number, since it is smaller than the sum of its proper divisors (992521792).

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

661396160 is a wasteful number, since it uses less digits than its factorization.

661396160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1202 (or 1192 counting only the distinct ones).

The product of its (nonzero) digits is 34992, while the sum is 38.

The square root of 661396160 is about 25717.6235294010. The cubic root of 661396160 is about 871.2722654862.

The spelling of 661396160 in words is "six hundred sixty-one million, three hundred ninety-six thousand, one hundred sixty".