1231808256 has 216 divisors, whose sum is σ = 4238561040. Its totient is φ = 351848448.

The previous prime is 1231808251. The next prime is 1231808261. The reversal of 1231808256 is 6528081321.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1231808251) and next prime (1231808261).

It is a tau number, because it is divible by the number of its divisors (216).

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

It is a self number, because there is not a number n which added to its sum of digits gives 1231808256.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1231808251) 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, 336870 + ... + 340506.

Almost surely, 2^1231808256 is an apocalyptic number.

1231808256 is a gapful number since it is divisible by the number (16) 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 1231808256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2119280520).

1231808256 is an abundant number, since it is smaller than the sum of its proper divisors (3006752784).

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

1231808256 is an equidigital number, since it uses as much as digits as its factorization.

1231808256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3676 (or 3649 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 1231808256 is about 35097.1260361871. The cubic root of 1231808256 is about 1071.9660641221.

Adding to 1231808256 its reverse (6528081321), we get a palindrome (7759889577).

The spelling of 1231808256 in words is "one billion, two hundred thirty-one million, eight hundred eight thousand, two hundred fifty-six".