249821649 has 60 divisors (see below), whose sum is σ = 459677712. Its totient is φ = 129654000.

The previous prime is 249821639. The next prime is 249821683. The reversal of 249821649 is 946128942.

It is not a de Polignac number, because 249821649 - 2⁸ = 249821393 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (249821639) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 237174 + ... + 238224.

Almost surely, 2^249821649 is an apocalyptic number.

It is an amenable number.

249821649 is a deficient number, since it is larger than the sum of its proper divisors (209856063).

249821649 is a wasteful number, since it uses less digits than its factorization.

249821649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1096 (or 1072 counting only the distinct ones).

The product of its digits is 248832, while the sum is 45.

The square root of 249821649 is about 15805.7473407618. The cubic root of 249821649 is about 629.8106838566.

The spelling of 249821649 in words is "two hundred forty-nine million, eight hundred twenty-one thousand, six hundred forty-nine".