1261251117 has 24 divisors (see below), whose sum is σ = 2085108480. Its totient is φ = 719661600.

The previous prime is 1261251113. The next prime is 1261251127. The reversal of 1261251117 is 7111521621.

1261251117 is a `hidden beast` number, since 126 + 12 + 511 + 17 = 666.

It is not a de Polignac number, because 1261251117 - 2² = 1261251113 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261251113) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 29884 + ... + 58442.

It is an arithmetic number, because the mean of its divisors is an integer number (86879520).

Almost surely, 2^1261251117 is an apocalyptic number.

It is an amenable number.

1261251117 is a deficient number, since it is larger than the sum of its proper divisors (823857363).

1261251117 is a wasteful number, since it uses less digits than its factorization.

1261251117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29273 (or 29270 counting only the distinct ones).

The product of its digits is 840, while the sum is 27.

The square root of 1261251117 is about 35514.0974403123. The cubic root of 1261251117 is about 1080.4396692369.

Adding to 1261251117 its reverse (7111521621), we get a palindrome (8372772738).

The spelling of 1261251117 in words is "one billion, two hundred sixty-one million, two hundred fifty-one thousand, one hundred seventeen".