1261012506 has 16 divisors (see below), whose sum is σ = 2716027104. Its totient is φ = 388003824.

The previous prime is 1261012409. The next prime is 1261012507. The reversal of 1261012506 is 6052101621.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1261012507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8083336 + ... + 8083491.

It is an arithmetic number, because the mean of its divisors is an integer number (169751694).

Almost surely, 2^1261012506 is an apocalyptic number.

1261012506 is an abundant number, since it is smaller than the sum of its proper divisors (1455014598).

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

1261012506 is a wasteful number, since it uses less digits than its factorization.

1261012506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16166845.

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 1261012506 is about 35510.7378971488. The cubic root of 1261012506 is about 1080.3715302687.

The spelling of 1261012506 in words is "one billion, two hundred sixty-one million, twelve thousand, five hundred six".