1251053503 has 4 divisors (see below), whose sum is σ = 1429775440. Its totient is φ = 1072331568.

The previous prime is 1251053491. The next prime is 1251053521. The reversal of 1251053503 is 3053501521.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1251053503 - 2⁵ = 1251053471 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1251053543) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 89360958 + ... + 89360971.

It is an arithmetic number, because the mean of its divisors is an integer number (357443860).

Almost surely, 2^1251053503 is an apocalyptic number.

1251053503 is a deficient number, since it is larger than the sum of its proper divisors (178721937).

1251053503 is an equidigital number, since it uses as much as digits as its factorization.

1251053503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178721936.

The product of its (nonzero) digits is 2250, while the sum is 25.

The square root of 1251053503 is about 35370.2347037732. The cubic root of 1251053503 is about 1077.5198871587.

It can be divided in two parts, 125105 and 3503, that multiplied together give a triangular number (438242815 = T₂₉₆₀₅).

The spelling of 1251053503 in words is "one billion, two hundred fifty-one million, fifty-three thousand, five hundred three".