1261172907 has 24 divisors (see below), whose sum is σ = 1885578240. Its totient is φ = 811445040.

The previous prime is 1261172903. The next prime is 1261172911. The reversal of 1261172907 is 7092711621.

It is a happy number.

1261172907 is a `hidden beast` number, since 12 + 611 + 7 + 29 + 0 + 7 = 666.

It is an interprime number because it is at equal distance from previous prime (1261172903) and next prime (1261172911).

It is not a de Polignac number, because 1261172907 - 2² = 1261172903 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1261172903) 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, 99778 + ... + 111704.

It is an arithmetic number, because the mean of its divisors is an integer number (78565760).

Almost surely, 2^1261172907 is an apocalyptic number.

1261172907 is a deficient number, since it is larger than the sum of its proper divisors (624405333).

1261172907 is a wasteful number, since it uses less digits than its factorization.

1261172907 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12343 (or 12340 counting only the distinct ones).

The product of its (nonzero) digits is 10584, while the sum is 36.

The square root of 1261172907 is about 35512.9963112098. The cubic root of 1261172907 is about 1080.4173361392.

The spelling of 1261172907 in words is "one billion, two hundred sixty-one million, one hundred seventy-two thousand, nine hundred seven".