681778944 has 540 divisors, whose sum is σ = 2622129048. Its totient is φ = 174182400.

The previous prime is 681778913. The next prime is 681778963. The reversal of 681778944 is 449877186.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (54).

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

Its product of digits (2709504) is a multiple of the sum of its prime divisors (84).

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 59 ways as a sum of consecutive naturals, for example, 11176674 + ... + 11176734.

Almost surely, 2^681778944 is an apocalyptic number.

681778944 is a gapful number since it is divisible by the number (64) 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 681778944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1311064524).

681778944 is an abundant number, since it is smaller than the sum of its proper divisors (1940350104).

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

681778944 is a wasteful number, since it uses less digits than its factorization.

681778944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114 (or 84 counting only the distinct ones).

The product of its digits is 2709504, while the sum is 54.

The square root of 681778944 is about 26110.8970355291. The cubic root of 681778944 is about 880.1321013807.

The spelling of 681778944 in words is "six hundred eighty-one million, seven hundred seventy-eight thousand, nine hundred forty-four".