248718521 has 4 divisors (see below), whose sum is σ = 250007412. Its totient is φ = 247429632.

The previous prime is 248718499. The next prime is 248718563. The reversal of 248718521 is 125817842.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 125817842 = 2 ⋅62908921.

It can be written as a sum of positive squares in 2 ways, for example, as 19044496 + 229674025 = 4364^2 + 15155^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-248718521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (248718581) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 644156 + ... + 644541.

It is an arithmetic number, because the mean of its divisors is an integer number (62501853).

Almost surely, 2^248718521 is an apocalyptic number.

It is an amenable number.

248718521 is a deficient number, since it is larger than the sum of its proper divisors (1288891).

248718521 is a wasteful number, since it uses less digits than its factorization.

248718521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1288890.

The product of its digits is 35840, while the sum is 38.

The square root of 248718521 is about 15770.8123126236. The cubic root of 248718521 is about 628.8823056449.

The spelling of 248718521 in words is "two hundred forty-eight million, seven hundred eighteen thousand, five hundred twenty-one".