1251155000 has 80 divisors (see below), whose sum is σ = 3011129880. Its totient is φ = 486864000.

The previous prime is 1251154999. The next prime is 1251155023. The reversal of 1251155000 is 5511521.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 181619 + ... + 188381.

Almost surely, 2^1251155000 is an apocalyptic number.

1251155000 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 1251155000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1505564940).

1251155000 is an abundant number, since it is smaller than the sum of its proper divisors (1759974880).

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

1251155000 is an equidigital number, since it uses as much as digits as its factorization.

1251155000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6826 (or 6807 counting only the distinct ones).

The product of its (nonzero) digits is 250, while the sum is 20.

The square root of 1251155000 is about 35371.6694545225. The cubic root of 1251155000 is about 1077.5490258215.

Adding to 1251155000 its reverse (5511521), we get a palindrome (1256666521).

The spelling of 1251155000 in words is "one billion, two hundred fifty-one million, one hundred fifty-five thousand".