249041521 has 2 divisors, whose sum is σ = 249041522. Its totient is φ = 249041520.

The previous prime is 249041519. The next prime is 249041543. The reversal of 249041521 is 125140942.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 242736400 + 6305121 = 15580^2 + 2511^2 .

It is a cyclic number.

It is not a de Polignac number, because 249041521 - 2¹ = 249041519 is a prime.

Together with 249041519, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 249041521.

It is not a weakly prime, because it can be changed into another prime (249041501) 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, 124520760 + 124520761.

It is an arithmetic number, because the mean of its divisors is an integer number (124520761).

Almost surely, 2^249041521 is an apocalyptic number.

It is an amenable number.

249041521 is a deficient number, since it is larger than the sum of its proper divisors (1).

249041521 is an equidigital number, since it uses as much as digits as its factorization.

249041521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 249041521 is about 15781.0494264482. The cubic root of 249041521 is about 629.1544219790.

It can be divided in two parts, 24904152 and 1, that added together give a triangular number (24904153 = T₇₀₅₇).

The spelling of 249041521 in words is "two hundred forty-nine million, forty-one thousand, five hundred twenty-one".