1721487664 has 80 divisors (see below), whose sum is σ = 3696638400. Its totient is φ = 771563520.

The previous prime is 1721487619. The next prime is 1721487683. The reversal of 1721487664 is 4667841271.

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, 2873637 + ... + 2874235.

It is an arithmetic number, because the mean of its divisors is an integer number (46207980).

Almost surely, 2^1721487664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1721487664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1848319200).

1721487664 is an abundant number, since it is smaller than the sum of its proper divisors (1975150736).

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

1721487664 is a wasteful number, since it uses less digits than its factorization.

1721487664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 998 (or 992 counting only the distinct ones).

The product of its digits is 451584, while the sum is 46.

The square root of 1721487664 is about 41490.8142123049. The cubic root of 1721487664 is about 1198.4906170802.

The spelling of 1721487664 in words is "one billion, seven hundred twenty-one million, four hundred eighty-seven thousand, six hundred sixty-four".