681915 has 24 divisors (see below), whose sum is σ = 1185840. Its totient is φ = 334464.

The previous prime is 681913. The next prime is 681931. The reversal of 681915 is 519186.

681915 = 223² + 224² + ... + 235².

It is a happy number.

It is not a de Polignac number, because 681915 - 2¹ = 681913 is a prime.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (681913) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 2401 + ... + 2669.

It is an arithmetic number, because the mean of its divisors is an integer number (49410).

2⁶⁸¹⁹¹⁵ is an apocalyptic number.

681915 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

681915 is a deficient number, since it is larger than the sum of its proper divisors (503925).

681915 is a wasteful number, since it uses less digits than its factorization.

681915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 303 (or 290 counting only the distinct ones).

The product of its digits is 2160, while the sum is 30.

The square root of 681915 is about 825.7814480842. The cubic root of 681915 is about 88.0190643957.

It can be divided in two parts, 681 and 915, that added together give a triangular number (1596 = T₅₆).

The spelling of 681915 in words is "six hundred eighty-one thousand, nine hundred fifteen".