1261438806 has 8 divisors (see below), whose sum is σ = 2522877624. Its totient is φ = 420479600.

The previous prime is 1261438751. The next prime is 1261438819. The reversal of 1261438806 is 6088341621.

It is a sphenic number, since it is the product of 3 distinct primes.

1261438806 is an admirable number.

It is a super-2 number, since 2×1261438806² = 3182455722565411272, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 105119895 + ... + 105119906.

It is an arithmetic number, because the mean of its divisors is an integer number (315359703).

Almost surely, 2^1261438806 is an apocalyptic number.

1261438806 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

1261438806 is a wasteful number, since it uses less digits than its factorization.

1261438806 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210239806.

The product of its (nonzero) digits is 55296, while the sum is 39.

The square root of 1261438806 is about 35516.7397997057. The cubic root of 1261438806 is about 1080.4932606220.

The spelling of 1261438806 in words is "one billion, two hundred sixty-one million, four hundred thirty-eight thousand, eight hundred six".