681378345 has 64 divisors (see below), whose sum is σ = 1259712000. Its totient is φ = 349026048.

The previous prime is 681378337. The next prime is 681378349. The reversal of 681378345 is 543873186.

It is not a de Polignac number, because 681378345 - 2³ = 681378337 is a prime.

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

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 681378345.

It is not an unprimeable number, because it can be changed into a prime (681378349) by changing a digit.

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 63 ways as a sum of consecutive naturals, for example, 1052812 + ... + 1053458.

It is an arithmetic number, because the mean of its divisors is an integer number (19683000).

Almost surely, 2^681378345 is an apocalyptic number.

It is an amenable number.

681378345 is a deficient number, since it is larger than the sum of its proper divisors (578333655).

681378345 is a wasteful number, since it uses less digits than its factorization.

681378345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 959 (or 953 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The square root of 681378345 is about 26103.2248007789. The cubic root of 681378345 is about 879.9596852227.

It can be divided in two parts, 6813 and 78345, that added together give a palindrome (85158).

The spelling of 681378345 in words is "six hundred eighty-one million, three hundred seventy-eight thousand, three hundred forty-five".