1181213857 has 2 divisors, whose sum is σ = 1181213858. Its totient is φ = 1181213856.

The previous prime is 1181213849. The next prime is 1181213867. The reversal of 1181213857 is 7583121811.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 915002001 + 266211856 = 30249^2 + 16316^2 .

It is a cyclic number.

It is not a de Polignac number, because 1181213857 - 2³ = 1181213849 is a prime.

It is not a weakly prime, because it can be changed into another prime (1181213867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 590606928 + 590606929.

It is an arithmetic number, because the mean of its divisors is an integer number (590606929).

Almost surely, 2^1181213857 is an apocalyptic number.

It is an amenable number.

1181213857 is a deficient number, since it is larger than the sum of its proper divisors (1).

1181213857 is an equidigital number, since it uses as much as digits as its factorization.

1181213857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13440, while the sum is 37.

The square root of 1181213857 is about 34368.7919048663. The cubic root of 1181213857 is about 1057.0840283022.

The spelling of 1181213857 in words is "one billion, one hundred eighty-one million, two hundred thirteen thousand, eight hundred fifty-seven".