1249806161 has 2 divisors, whose sum is σ = 1249806162. Its totient is φ = 1249806160.

The previous prime is 1249806139. The next prime is 1249806179. The reversal of 1249806161 is 1616089421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 780867136 + 468939025 = 27944^2 + 21655^2 .

It is a cyclic number.

It is not a de Polignac number, because 1249806161 - 2¹⁸ = 1249544017 is a prime.

It is not a weakly prime, because it can be changed into another prime (1249806101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 624903080 + 624903081.

It is an arithmetic number, because the mean of its divisors is an integer number (624903081).

Almost surely, 2^1249806161 is an apocalyptic number.

It is an amenable number.

1249806161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1249806161 is an equidigital number, since it uses as much as digits as its factorization.

1249806161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20736, while the sum is 38.

The square root of 1249806161 is about 35352.5976556179. The cubic root of 1249806161 is about 1077.1616603420.

The spelling of 1249806161 in words is "one billion, two hundred forty-nine million, eight hundred six thousand, one hundred sixty-one".