661368128 has 28 divisors (see below), whose sum is σ = 1369466400. Its totient is φ = 316305792.

The previous prime is 661368107. The next prime is 661368139. The reversal of 661368128 is 821863166.

661368128 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 223178 + ... + 226121.

Almost surely, 2^661368128 is an apocalyptic number.

It is an amenable number.

661368128 is an abundant number, since it is smaller than the sum of its proper divisors (708098272).

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

661368128 is a wasteful number, since it uses less digits than its factorization.

661368128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 449334 (or 449324 counting only the distinct ones).

The product of its digits is 82944, while the sum is 41.

The square root of 661368128 is about 25717.0785277022. The cubic root of 661368128 is about 871.2599562477.

The spelling of 661368128 in words is "six hundred sixty-one million, three hundred sixty-eight thousand, one hundred twenty-eight".