1249921181 has 2 divisors, whose sum is σ = 1249921182. Its totient is φ = 1249921180.

The previous prime is 1249921163. The next prime is 1249921193. The reversal of 1249921181 is 1811299421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1106161081 + 143760100 = 33259^2 + 11990^2 .

It is a cyclic number.

It is not a de Polignac number, because 1249921181 - 2³⁰ = 176179357 is a prime.

It is a super-2 number, since 2×1249921181² = 3124605917424869522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1249921151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 624960590 + 624960591.

It is an arithmetic number, because the mean of its divisors is an integer number (624960591).

Almost surely, 2^1249921181 is an apocalyptic number.

It is an amenable number.

1249921181 is a deficient number, since it is larger than the sum of its proper divisors (1).

1249921181 is an equidigital number, since it uses as much as digits as its factorization.

1249921181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 38.

The square root of 1249921181 is about 35354.2243727677. The cubic root of 1249921181 is about 1077.1947031550.

The spelling of 1249921181 in words is "one billion, two hundred forty-nine million, nine hundred twenty-one thousand, one hundred eighty-one".