1231840 has 24 divisors (see below), whose sum is σ = 2910600. Its totient is φ = 492672.

The previous prime is 1231831. The next prime is 1231843. The reversal of 1231840 is 481321.

1231840 = 106² + 107² + ... + 169².

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231843) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3690 + ... + 4009.

It is an arithmetic number, because the mean of its divisors is an integer number (121275).

2^1231840 is an apocalyptic number.

1231840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1231840 is an abundant number, since it is smaller than the sum of its proper divisors (1678760).

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

1231840 is an equidigital number, since it uses as much as digits as its factorization.

1231840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7714 (or 7706 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 1231840 is about 1109.8828767037. The cubic root of 1231840 is about 107.1975272319.

The spelling of 1231840 in words is "one million, two hundred thirty-one thousand, eight hundred forty".