1261278485 has 16 divisors (see below), whose sum is σ = 1580342400. Its totient is φ = 964539840.

The previous prime is 1261278437. The next prime is 1261278547. The reversal of 1261278485 is 5848721621.

It is not a de Polignac number, because 1261278485 - 2¹⁰ = 1261277461 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 274991 + ... + 279539.

It is an arithmetic number, because the mean of its divisors is an integer number (98771400).

Almost surely, 2^1261278485 is an apocalyptic number.

It is an amenable number.

1261278485 is a deficient number, since it is larger than the sum of its proper divisors (319063915).

1261278485 is a wasteful number, since it uses less digits than its factorization.

1261278485 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6988.

The product of its digits is 215040, while the sum is 44.

The square root of 1261278485 is about 35514.4827499993. The cubic root of 1261278485 is about 1080.4474840325.

The spelling of 1261278485 in words is "one billion, two hundred sixty-one million, two hundred seventy-eight thousand, four hundred eighty-five".