1261728825 has 48 divisors (see below), whose sum is σ = 2487745536. Its totient is φ = 551707200.

The previous prime is 1261728817. The next prime is 1261728827. The reversal of 1261728825 is 5288271621.

It is not a de Polignac number, because 1261728825 - 2³ = 1261728817 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1261728827) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 40171 + ... + 64320.

It is an arithmetic number, because the mean of its divisors is an integer number (51828032).

Almost surely, 2^1261728825 is an apocalyptic number.

1261728825 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1261728825 is a deficient number, since it is larger than the sum of its proper divisors (1226016711).

1261728825 is a wasteful number, since it uses less digits than its factorization.

1261728825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104534 (or 104529 counting only the distinct ones).

The product of its digits is 107520, while the sum is 42.

The square root of 1261728825 is about 35520.8224144656. The cubic root of 1261728825 is about 1080.5760601366.

The spelling of 1261728825 in words is "one billion, two hundred sixty-one million, seven hundred twenty-eight thousand, eight hundred twenty-five".