661402304 has 56 divisors (see below), whose sum is σ = 1362516960. Its totient is φ = 318173184.

The previous prime is 661402297. The next prime is 661402309. The reversal of 661402304 is 403204166.

It is not an unprimeable number, because it can be changed into a prime (661402309) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 803237 + ... + 804059.

It is an arithmetic number, because the mean of its divisors is an integer number (24330660).

Almost surely, 2^661402304 is an apocalyptic number.

661402304 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 661402304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (681258480).

661402304 is an abundant number, since it is smaller than the sum of its proper divisors (701114656).

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

661402304 is a wasteful number, since it uses less digits than its factorization.

661402304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1297 (or 1287 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 661402304 is about 25717.7429802850. The cubic root of 661402304 is about 871.2749633550.

The spelling of 661402304 in words is "six hundred sixty-one million, four hundred two thousand, three hundred four".