1251505000 has 40 divisors (see below), whose sum is σ = 2932287930. Its totient is φ = 500600000.

The previous prime is 1251504941. The next prime is 1251505007. The reversal of 1251505000 is 5051521.

It can be written as a sum of positive squares in 5 ways, for example, as 108118404 + 1143386596 = 10398^2 + 33814^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (1251505007) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 120151 + ... + 130150.

Almost surely, 2^1251505000 is an apocalyptic number.

1251505000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1251505000 is an abundant number, since it is smaller than the sum of its proper divisors (1680782930).

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

1251505000 is an equidigital number, since it uses as much as digits as its factorization.

1251505000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250327 (or 250308 counting only the distinct ones).

The product of its (nonzero) digits is 250, while the sum is 19.

The square root of 1251505000 is about 35376.6165708367. The cubic root of 1251505000 is about 1077.6494948540.

Adding to 1251505000 its reverse (5051521), we get a palindrome (1256556521).

The spelling of 1251505000 in words is "one billion, two hundred fifty-one million, five hundred five thousand".