1261947871 has 8 divisors (see below), whose sum is σ = 1333540080. Its totient is φ = 1190873088.

The previous prime is 1261947839. The next prime is 1261947889. The reversal of 1261947871 is 1787491621.

It is a happy number.

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 1261947871 - 2⁵ = 1261947839 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261947671) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 124336 + ... + 134101.

It is an arithmetic number, because the mean of its divisors is an integer number (166692510).

Almost surely, 2^1261947871 is an apocalyptic number.

1261947871 is a deficient number, since it is larger than the sum of its proper divisors (71592209).

1261947871 is a wasteful number, since it uses less digits than its factorization.

1261947871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 258713.

The product of its digits is 169344, while the sum is 46.

The square root of 1261947871 is about 35523.9056270563. The cubic root of 1261947871 is about 1080.6385886723.

The spelling of 1261947871 in words is "one billion, two hundred sixty-one million, nine hundred forty-seven thousand, eight hundred seventy-one".