1721643120 has 80 divisors (see below), whose sum is σ = 5930111520. Its totient is φ = 459104256.

The previous prime is 1721643113. The next prime is 1721643139. The reversal of 1721643120 is 213461271.

1721643120 is a `hidden beast` number, since 1 + 7 + 2 + 1 + 643 + 12 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 396369 + ... + 400688.

It is an arithmetic number, because the mean of its divisors is an integer number (74126394).

Almost surely, 2^1721643120 is an apocalyptic number.

1721643120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1721643120 is an abundant number, since it is smaller than the sum of its proper divisors (4208468400).

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

1721643120 is a wasteful number, since it uses less digits than its factorization.

1721643120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 797079 (or 797067 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 1721643120 is about 41492.6875485308. The cubic root of 1721643120 is about 1198.5266918763.

The spelling of 1721643120 in words is "one billion, seven hundred twenty-one million, six hundred forty-three thousand, one hundred twenty".