1681268736 has 224 divisors, whose sum is σ = 5315955840. Its totient is φ = 462422016.

The previous prime is 1681268731. The next prime is 1681268759. The reversal of 1681268736 is 6378621861.

It is a tau number, because it is divible by the number of its divisors (224).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a nude number because it is divisible by every one of its digits.

Its product of digits (580608) is a multiple of the sum of its prime divisors (378).

It is not an unprimeable number, because it can be changed into a prime (1681268731) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4988760 + ... + 4989096.

Almost surely, 2^1681268736 is an apocalyptic number.

1681268736 is a gapful number since it is divisible by the number (16) 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 1681268736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2657977920).

1681268736 is an abundant number, since it is smaller than the sum of its proper divisors (3634687104).

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

1681268736 is an equidigital number, since it uses as much as digits as its factorization.

1681268736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 402 (or 378 counting only the distinct ones).

The product of its digits is 580608, while the sum is 48.

The square root of 1681268736 is about 41003.2771373216. The cubic root of 1681268736 is about 1189.0835719086.

The spelling of 1681268736 in words is "one billion, six hundred eighty-one million, two hundred sixty-eight thousand, seven hundred thirty-six".