249158821 has 2 divisors, whose sum is σ = 249158822. Its totient is φ = 249158820.

The previous prime is 249158803. The next prime is 249158929. The reversal of 249158821 is 128851942.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 127938721 + 121220100 = 11311^2 + 11010^2 .

It is a cyclic number.

It is not a de Polignac number, because 249158821 - 2⁹ = 249158309 is a prime.

It is a super-2 number, since 2×249158821² = 124160236164220082, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (249158801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124579410 + 124579411.

It is an arithmetic number, because the mean of its divisors is an integer number (124579411).

Almost surely, 2^249158821 is an apocalyptic number.

It is an amenable number.

249158821 is a deficient number, since it is larger than the sum of its proper divisors (1).

249158821 is an equidigital number, since it uses as much as digits as its factorization.

249158821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 46080, while the sum is 40.

The square root of 249158821 is about 15784.7654718086. The cubic root of 249158821 is about 629.2531849346.

The spelling of 249158821 in words is "two hundred forty-nine million, one hundred fifty-eight thousand, eight hundred twenty-one".