1261847279 has 8 divisors (see below), whose sum is σ = 1573212288. Its totient is φ = 983257560.

The previous prime is 1261847263. The next prime is 1261847299. The reversal of 1261847279 is 9727481621.

Added to its reverse (9727481621) it gives a square (10989328900 = 104830²).

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

It is a cyclic number.

It is not a de Polignac number, because 1261847279 - 2⁴ = 1261847263 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 (1261847239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8193737 + ... + 8193890.

It is an arithmetic number, because the mean of its divisors is an integer number (196651536).

Almost surely, 2^1261847279 is an apocalyptic number.

1261847279 is a deficient number, since it is larger than the sum of its proper divisors (311365009).

1261847279 is a wasteful number, since it uses less digits than its factorization.

1261847279 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16387645.

The product of its digits is 338688, while the sum is 47.

The square root of 1261847279 is about 35522.4897635287. The cubic root of 1261847279 is about 1080.6098747326.

Adding to 1261847279 its reverse (9727481621), we get a square (10989328900 = 104830²).

The spelling of 1261847279 in words is "one billion, two hundred sixty-one million, eight hundred forty-seven thousand, two hundred seventy-nine".