249266821 has 4 divisors (see below), whose sum is σ = 249301612. Its totient is φ = 249232032.

The previous prime is 249266789. The next prime is 249266827. The reversal of 249266821 is 128662942.

249266821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is the 6446-th star number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 190053796 + 59213025 = 13786^2 + 7695^2 .

It is a cyclic number.

It is not a de Polignac number, because 249266821 - 2⁵ = 249266789 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (249266827) 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, 2256 + ... + 22441.

It is an arithmetic number, because the mean of its divisors is an integer number (62325403).

Almost surely, 2^249266821 is an apocalyptic number.

It is an amenable number.

249266821 is a deficient number, since it is larger than the sum of its proper divisors (34791).

249266821 is a wasteful number, since it uses less digits than its factorization.

249266821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34790.

The product of its digits is 82944, while the sum is 40.

The square root of 249266821 is about 15788.1861212743. The cubic root of 249266821 is about 629.3440901745.

The spelling of 249266821 in words is "two hundred forty-nine million, two hundred sixty-six thousand, eight hundred twenty-one".