1681928640 has 336 divisors, whose sum is σ = 6961144320. Its totient is φ = 364124160.

The previous prime is 1681928639. The next prime is 1681928641. The reversal of 1681928640 is 468291861.

It is an interprime number because it is at equal distance from previous prime (1681928639) and next prime (1681928641).

It is a tau number, because it is divible by the number of its divisors (336).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1681928641) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 380845 + ... + 385235.

Almost surely, 2^1681928640 is an apocalyptic number.

1681928640 is a gapful number since it is divisible by the number (10) 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 1681928640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3480572160).

1681928640 is an abundant number, since it is smaller than the sum of its proper divisors (5279215680).

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

1681928640 is a wasteful number, since it uses less digits than its factorization.

1681928640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4440 (or 4427 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 45.

The square root of 1681928640 is about 41011.3233144213. The cubic root of 1681928640 is about 1189.2391247455.

The spelling of 1681928640 in words is "one billion, six hundred eighty-one million, nine hundred twenty-eight thousand, six hundred forty".