249071521 has 2 divisors, whose sum is σ = 249071522. Its totient is φ = 249071520.

The previous prime is 249071507. The next prime is 249071533. The reversal of 249071521 is 125170942.

249071521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 223921296 + 25150225 = 14964^2 + 5015^2 .

It is a cyclic number.

It is not a de Polignac number, because 249071521 - 2¹⁷ = 248940449 is a prime.

It is not a weakly prime, because it can be changed into another prime (249071561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124535760 + 124535761.

It is an arithmetic number, because the mean of its divisors is an integer number (124535761).

Almost surely, 2^249071521 is an apocalyptic number.

It is an amenable number.

249071521 is a deficient number, since it is larger than the sum of its proper divisors (1).

249071521 is an equidigital number, since it uses as much as digits as its factorization.

249071521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5040, while the sum is 31.

The square root of 249071521 is about 15781.9999049550. Note that the first 4 decimals coincide. The cubic root of 249071521 is about 629.1796839979.

The spelling of 249071521 in words is "two hundred forty-nine million, seventy-one thousand, five hundred twenty-one".