249780813 has 16 divisors (see below), whose sum is σ = 353477376. Its totient is φ = 156349440.

The previous prime is 249780809. The next prime is 249780829. The reversal of 249780813 is 318087942.

It is not a de Polignac number, because 249780813 - 2² = 249780809 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (249780863) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16428 + ... + 27738.

It is an arithmetic number, because the mean of its divisors is an integer number (22092336).

Almost surely, 2^249780813 is an apocalyptic number.

It is an amenable number.

249780813 is a deficient number, since it is larger than the sum of its proper divisors (103696563).

249780813 is a wasteful number, since it uses less digits than its factorization.

249780813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11764.

The product of its (nonzero) digits is 96768, while the sum is 42.

The square root of 249780813 is about 15804.4554793893. The cubic root of 249780813 is about 629.7763655730.

The spelling of 249780813 in words is "two hundred forty-nine million, seven hundred eighty thousand, eight hundred thirteen".