1251530240 has 40 divisors (see below), whose sum is σ = 3000745440. Its totient is φ = 500611072.

The previous prime is 1251530239. The next prime is 1251530251. The reversal of 1251530240 is 420351521.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 241880 + ... + 246999.

It is an arithmetic number, because the mean of its divisors is an integer number (75018636).

Almost surely, 2^1251530240 is an apocalyptic number.

1251530240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1251530240 is an abundant number, since it is smaller than the sum of its proper divisors (1749215200).

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

1251530240 is an frugal number, since it uses more digits than its factorization.

1251530240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 488902 (or 488886 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 1251530240 is about 35376.9733018527. The cubic root of 1251530240 is about 1077.6567393823.

Adding to 1251530240 its reverse (420351521), we get a palindrome (1671881761).

The spelling of 1251530240 in words is "one billion, two hundred fifty-one million, five hundred thirty thousand, two hundred forty".