1721820672 has 480 divisors, whose sum is σ = 6110501760. Its totient is φ = 474439680.

The previous prime is 1721820637. The next prime is 1721820691. The reversal of 1721820672 is 2760281271.

It is a super-3 number, since 3×1721820672³ (a number of 29 digits) contains 333 as substring.

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

It is a congruent number.

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 47 ways as a sum of consecutive naturals, for example, 25698783 + ... + 25698849.

It is an arithmetic number, because the mean of its divisors is an integer number (12730212).

Almost surely, 2^1721820672 is an apocalyptic number.

1721820672 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1721820672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3055250880).

1721820672 is an abundant number, since it is smaller than the sum of its proper divisors (4388681088).

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

1721820672 is a wasteful number, since it uses less digits than its factorization.

1721820672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131 (or 96 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 1721820672 is about 41494.8270510916. The cubic root of 1721820672 is about 1198.5678915678.

The spelling of 1721820672 in words is "one billion, seven hundred twenty-one million, eight hundred twenty thousand, six hundred seventy-two".