681450840 has 384 divisors, whose sum is σ = 2692224000. Its totient is φ = 152845056.

The previous prime is 681450823. The next prime is 681450841. The reversal of 681450840 is 48054186.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 681450795 and 681450804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681450841) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4180599 + ... + 4180761.

It is an arithmetic number, because the mean of its divisors is an integer number (7011000).

Almost surely, 2^681450840 is an apocalyptic number.

681450840 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 681450840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1346112000).

681450840 is an abundant number, since it is smaller than the sum of its proper divisors (2010773160).

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

681450840 is a wasteful number, since it uses less digits than its factorization.

681450840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276 (or 259 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 36.

The square root of 681450840 is about 26104.6133853769. The cubic root of 681450840 is about 879.9908917790.

The spelling of 681450840 in words is "six hundred eighty-one million, four hundred fifty thousand, eight hundred forty".