661336704 has 128 divisors (see below), whose sum is σ = 2230780800. Its totient is φ = 188946432.

The previous prime is 661336693. The next prime is 661336717. The reversal of 661336704 is 407633166.

It is a happy number.

661336704 is a `hidden beast` number, since 6 + 613 + 36 + 7 + 0 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (128).

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

It is a congruent 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, 10524 + ... + 37860.

It is an arithmetic number, because the mean of its divisors is an integer number (17427975).

Almost surely, 2^661336704 is an apocalyptic number.

661336704 is a gapful number since it is divisible by the number (64) 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 661336704, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1115390400).

661336704 is an abundant number, since it is smaller than the sum of its proper divisors (1569444096).

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

661336704 is a wasteful number, since it uses less digits than its factorization.

661336704 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27367 (or 27349 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 36.

The square root of 661336704 is about 25716.4675645781. The cubic root of 661336704 is about 871.2461571216.

The spelling of 661336704 in words is "six hundred sixty-one million, three hundred thirty-six thousand, seven hundred four".