312840 has 96 divisors (see below), whose sum is σ = 1123200. Its totient is φ = 74880.

The previous prime is 312839. The next prime is 312841. The reversal of 312840 is 48213.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (312839) and next prime (312841).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (312841) 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, 3921 + ... + 3999.

It is an arithmetic number, because the mean of its divisors is an integer number (11700).

2³¹²⁸⁴⁰ is an apocalyptic number.

312840 is a gapful number since it is divisible by the number (30) 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 312840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (561600).

312840 is an abundant number, since it is smaller than the sum of its proper divisors (810360).

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

312840 is a wasteful number, since it uses less digits than its factorization.

312840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107 (or 100 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 312840 is about 559.3210169482. The cubic root of 312840 is about 67.8850422145.

The spelling of 312840 in words is "three hundred twelve thousand, eight hundred forty".