2173205664 has 108 divisors (see below), whose sum is σ = 7189088634. Its totient is φ = 620911872.

The previous prime is 2173205653. The next prime is 2173205689. The reversal of 2173205664 is 4665023712.

2173205664 is a `hidden beast` number, since 2 + 1 + 73 + 20 + 566 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1592010000 + 581195664 = 39900^2 + 24108^2 .

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

It is an unprimeable number.

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 17 ways as a sum of consecutive naturals, for example, 62887 + ... + 91110.

Almost surely, 2^2173205664 is an apocalyptic number.

2173205664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

2173205664 is an abundant number, since it is smaller than the sum of its proper divisors (5015882970).

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

2173205664 is a wasteful number, since it uses less digits than its factorization.

2173205664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154027 (or 154009 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 36.

The square root of 2173205664 is about 46617.6539950264. The cubic root of 2173205664 is about 1295.2897914893.

The spelling of 2173205664 in words is "two billion, one hundred seventy-three million, two hundred five thousand, six hundred sixty-four".