661545648 has 60 divisors (see below), whose sum is σ = 1948859640. Its totient is φ = 208908288.

The previous prime is 661545641. The next prime is 661545679. The reversal of 661545648 is 846545166.

661545648 is a `hidden beast` number, since 6 + 61 + 545 + 6 + 48 = 666.

661545648 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (661545641) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 118161 + ... + 123632.

It is an arithmetic number, because the mean of its divisors is an integer number (32480994).

Almost surely, 2^661545648 is an apocalyptic number.

It is an amenable number.

661545648 is an abundant number, since it is smaller than the sum of its proper divisors (1287313992).

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

661545648 is a wasteful number, since it uses less digits than its factorization.

661545648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241826 (or 241817 counting only the distinct ones).

The product of its digits is 691200, while the sum is 45.

The square root of 661545648 is about 25720.5296990556. The cubic root of 661545648 is about 871.3379018601.

The spelling of 661545648 in words is "six hundred sixty-one million, five hundred forty-five thousand, six hundred forty-eight".