248213821 has 8 divisors (see below), whose sum is σ = 263128824. Its totient is φ = 233333760.

The previous prime is 248213809. The next prime is 248213827. The reversal of 248213821 is 128312842.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 48302500 + 199911321 = 6950^2 + 14139^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 248213821 - 2²¹ = 246116669 is a prime.

It is a super-2 number, since 2×248213821² = 123220201870840082, which contains 22 as substring.

It is a Duffinian number.

248213821 is a modest number, since divided by 13821 gives 2482 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (248213827) 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 in 7 ways as a sum of consecutive naturals, for example, 6691 + ... + 23263.

It is an arithmetic number, because the mean of its divisors is an integer number (32891103).

Almost surely, 2^248213821 is an apocalyptic number.

It is an amenable number.

248213821 is a deficient number, since it is larger than the sum of its proper divisors (14915003).

248213821 is a wasteful number, since it uses less digits than its factorization.

248213821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17471.

The product of its digits is 6144, while the sum is 31.

The square root of 248213821 is about 15754.8031088935. The cubic root of 248213821 is about 628.4566412859.

The spelling of 248213821 in words is "two hundred forty-eight million, two hundred thirteen thousand, eight hundred twenty-one".