249765121 has 2 divisors, whose sum is σ = 249765122. Its totient is φ = 249765120.

The previous prime is 249765101. The next prime is 249765137. The reversal of 249765121 is 121567942.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 127441521 + 122323600 = 11289^2 + 11060^2 .

It is a cyclic number.

It is not a de Polignac number, because 249765121 - 2¹⁹ = 249240833 is a prime.

It is not a weakly prime, because it can be changed into another prime (249765101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124882560 + 124882561.

It is an arithmetic number, because the mean of its divisors is an integer number (124882561).

Almost surely, 2^249765121 is an apocalyptic number.

It is an amenable number.

249765121 is a deficient number, since it is larger than the sum of its proper divisors (1).

249765121 is an equidigital number, since it uses as much as digits as its factorization.

249765121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30240, while the sum is 37.

The square root of 249765121 is about 15803.9590293065. The cubic root of 249765121 is about 629.7631771332.

The spelling of 249765121 in words is "two hundred forty-nine million, seven hundred sixty-five thousand, one hundred twenty-one".