1249085861 has 2 divisors, whose sum is σ = 1249085862. Its totient is φ = 1249085860.

The previous prime is 1249085857. The next prime is 1249085953. The reversal of 1249085861 is 1685809421.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1082804836 + 166281025 = 32906^2 + 12895^2 .

It is an emirp because it is prime and its reverse (1685809421) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1249085861 - 2² = 1249085857 is a prime.

It is a super-2 number, since 2×1249085861² = 3120430976300222642, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1249385861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 624542930 + 624542931.

It is an arithmetic number, because the mean of its divisors is an integer number (624542931).

Almost surely, 2^1249085861 is an apocalyptic number.

It is an amenable number.

1249085861 is a deficient number, since it is larger than the sum of its proper divisors (1).

1249085861 is an equidigital number, since it uses as much as digits as its factorization.

1249085861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 138240, while the sum is 44.

The square root of 1249085861 is about 35342.4088171703. The cubic root of 1249085861 is about 1076.9546872743.

The spelling of 1249085861 in words is "one billion, two hundred forty-nine million, eighty-five thousand, eight hundred sixty-one".