1249551869 has 2 divisors, whose sum is σ = 1249551870. Its totient is φ = 1249551868.

The previous prime is 1249551841. The next prime is 1249551887. The reversal of 1249551869 is 9681559421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1156680100 + 92871769 = 34010^2 + 9637^2 .

It is a cyclic number.

It is not a de Polignac number, because 1249551869 - 2¹² = 1249547773 is a prime.

It is a super-2 number, since 2×1249551869² = 3122759746642786322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1249551899) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 624775934 + 624775935.

It is an arithmetic number, because the mean of its divisors is an integer number (624775935).

Almost surely, 2^1249551869 is an apocalyptic number.

It is an amenable number.

1249551869 is a deficient number, since it is larger than the sum of its proper divisors (1).

1249551869 is an equidigital number, since it uses as much as digits as its factorization.

1249551869 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 777600, while the sum is 50.

The square root of 1249551869 is about 35349.0009618377. Note that the first 3 decimals coincide. The cubic root of 1249551869 is about 1077.0886004333.

The spelling of 1249551869 in words is "one billion, two hundred forty-nine million, five hundred fifty-one thousand, eight hundred sixty-nine".