1661055872 has 32 divisors (see below), whose sum is σ = 3781870320. Its totient is φ = 711880704.

The previous prime is 1661055871. The next prime is 1661055887. The reversal of 1661055872 is 2785501661.

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661055871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 926033 + ... + 927824.

Almost surely, 2^1661055872 is an apocalyptic number.

It is an amenable number.

1661055872 is an abundant number, since it is smaller than the sum of its proper divisors (2120814448).

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

1661055872 is an equidigital number, since it uses as much as digits as its factorization.

1661055872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1853878 (or 1853866 counting only the distinct ones).

The product of its (nonzero) digits is 100800, while the sum is 41.

The square root of 1661055872 is about 40756.0531945869. The cubic root of 1661055872 is about 1184.2991391710.

The spelling of 1661055872 in words is "one billion, six hundred sixty-one million, fifty-five thousand, eight hundred seventy-two".