1681517664 has 96 divisors (see below), whose sum is σ = 4918717440. Its totient is φ = 558873216.

The previous prime is 1681517657. The next prime is 1681517681. The reversal of 1681517664 is 4667151861.

It is a tau number, because it is divible by the number of its divisors (96).

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, 314437 + ... + 319739.

It is an arithmetic number, because the mean of its divisors is an integer number (51236640).

Almost surely, 2^1681517664 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 1681517664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2459358720).

1681517664 is an abundant number, since it is smaller than the sum of its proper divisors (3237199776).

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

1681517664 is a wasteful number, since it uses less digits than its factorization.

1681517664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5689 (or 5675 counting only the distinct ones).

The product of its digits is 241920, while the sum is 45.

The square root of 1681517664 is about 41006.3124896643. The cubic root of 1681517664 is about 1189.1422540974.

The spelling of 1681517664 in words is "one billion, six hundred eighty-one million, five hundred seventeen thousand, six hundred sixty-four".