681877440 has 392 divisors, whose sum is σ = 2531912640. Its totient is φ = 174680064.

The previous prime is 681877381. The next prime is 681877487. The reversal of 681877440 is 44778186.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 8631321 + ... + 8631399.

Almost surely, 2^681877440 is an apocalyptic number.

681877440 is a gapful number since it is divisible by the number (60) 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 681877440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1265956320).

681877440 is an abundant number, since it is smaller than the sum of its proper divisors (1850035200).

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

681877440 is an equidigital number, since it uses as much as digits as its factorization.

681877440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151 (or 126 counting only the distinct ones).

The product of its (nonzero) digits is 301056, while the sum is 45.

The square root of 681877440 is about 26112.7830764934. The cubic root of 681877440 is about 880.1744833081.

The spelling of 681877440 in words is "six hundred eighty-one million, eight hundred seventy-seven thousand, four hundred forty".