1261159503 has 4 divisors (see below), whose sum is σ = 1681546008. Its totient is φ = 840773000.

The previous prime is 1261159489. The next prime is 1261159531. The reversal of 1261159503 is 3059511621.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3059511621 = 3 ⋅1019837207.

It is a cyclic number.

It is not a de Polignac number, because 1261159503 - 2⁸ = 1261159247 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261159553) 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, 210193248 + ... + 210193253.

It is an arithmetic number, because the mean of its divisors is an integer number (420386502).

Almost surely, 2^1261159503 is an apocalyptic number.

1261159503 is a deficient number, since it is larger than the sum of its proper divisors (420386505).

1261159503 is an equidigital number, since it uses as much as digits as its factorization.

1261159503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 420386504.

The product of its (nonzero) digits is 8100, while the sum is 33.

The square root of 1261159503 is about 35512.8075910649. The cubic root of 1261159503 is about 1080.4135084945.

The spelling of 1261159503 in words is "one billion, two hundred sixty-one million, one hundred fifty-nine thousand, five hundred three".