689940 has 36 divisors (see below), whose sum is σ = 2093364. Its totient is φ = 183936.

The previous prime is 689929. The next prime is 689951. The reversal of 689940 is 49986.

It is an interprime number because it is at equal distance from previous prime (689929) and next prime (689951).

It can be written as a sum of positive squares in 2 ways, for example, as 197136 + 492804 = 444^2 + 702^2 .

It is a tau number, because it is divible by the number of its divisors (36).

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

It is a nialpdrome in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 689895 and 689904.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1737 + ... + 2096.

It is an arithmetic number, because the mean of its divisors is an integer number (58149).

2⁶⁸⁹⁹⁴⁰ is an apocalyptic number.

689940 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

689940 is an abundant number, since it is smaller than the sum of its proper divisors (1403424).

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

689940 is a wasteful number, since it uses less digits than its factorization.

689940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3848 (or 3843 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 689940 is about 830.6262697507. The cubic root of 689940 is about 88.3629978292.

The spelling of 689940 in words is "six hundred eighty-nine thousand, nine hundred forty".