1243000000 has 196 divisors, whose sum is σ = 3393237816. Its totient is φ = 448000000.

The previous prime is 1242999973. The next prime is 1243000009. The reversal of 1243000000 is 3421.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is not an unprimeable number, because it can be changed into a prime (1243000009) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 10999944 + ... + 11000056.

Almost surely, 2^1243000000 is an apocalyptic number.

1243000000 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 1243000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1696618908).

1243000000 is an abundant number, since it is smaller than the sum of its proper divisors (2150237816).

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

1243000000 is an frugal number, since it uses more digits than its factorization.

1243000000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166 (or 131 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 10.

The square root of 1243000000 is about 35256.2051276084. The cubic root of 1243000000 is about 1075.2027740799.

Adding to 1243000000 its reverse (3421), we get a palindrome (1243003421).

The spelling of 1243000000 in words is "one billion, two hundred forty-three million", and thus it is an aban number.