690840 has 96 divisors (see below), whose sum is σ = 2386800. Its totient is φ = 172800.

The previous prime is 690839. The next prime is 690841. The reversal of 690840 is 48096.

It is an interprime number because it is at equal distance from previous prime (690839) and next prime (690841).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (690841) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6790 + ... + 6890.

2⁶⁹⁰⁸⁴⁰ is an apocalyptic number.

690840 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 690840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1193400).

690840 is an abundant number, since it is smaller than the sum of its proper divisors (1695960).

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

690840 is a wasteful number, since it uses less digits than its factorization.

690840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137 (or 130 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 690840 is about 831.1678530838. The cubic root of 690840 is about 88.4014031704.

The spelling of 690840 in words is "six hundred ninety thousand, eight hundred forty".