1261069857 has 32 divisors (see below), whose sum is σ = 1886976000. Its totient is φ = 832335120.

The previous prime is 1261069847. The next prime is 1261069903. The reversal of 1261069857 is 7589601621.

It is not a de Polignac number, because 1261069857 - 2¹⁶ = 1261004321 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (1261069847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1502644 + ... + 1503482.

It is an arithmetic number, because the mean of its divisors is an integer number (58968000).

Almost surely, 2^1261069857 is an apocalyptic number.

It is an amenable number.

1261069857 is a deficient number, since it is larger than the sum of its proper divisors (625906143).

1261069857 is a wasteful number, since it uses less digits than its factorization.

1261069857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1338 (or 1332 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 45.

The square root of 1261069857 is about 35511.5454042766. The cubic root of 1261069857 is about 1080.3879084960.

The spelling of 1261069857 in words is "one billion, two hundred sixty-one million, sixty-nine thousand, eight hundred fifty-seven".