1261231800 has 96 divisors (see below), whose sum is σ = 3919890480. Its totient is φ = 335462400.

The previous prime is 1261231747. The next prime is 1261231801. The reversal of 1261231800 is 81321621.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261231801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 250104 + ... + 255096.

Almost surely, 2^1261231800 is an apocalyptic number.

1261231800 is a gapful number since it is divisible by the number (10) 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 1261231800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1959945240).

1261231800 is an abundant number, since it is smaller than the sum of its proper divisors (2658658680).

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

1261231800 is a wasteful number, since it uses less digits than its factorization.

1261231800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5433 (or 5424 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 1261231800 is about 35513.8254768477. The cubic root of 1261231800 is about 1080.4341532960.

The spelling of 1261231800 in words is "one billion, two hundred sixty-one million, two hundred thirty-one thousand, eight hundred".