249999813 has 36 divisors (see below), whose sum is σ = 422547840. Its totient is φ = 142014096.

The previous prime is 249999809. The next prime is 249999817. The reversal of 249999813 is 318999942.

It is an interprime number because it is at equal distance from previous prime (249999809) and next prime (249999817).

It is not a de Polignac number, because 249999813 - 2² = 249999809 is a prime.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 249999813.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (249999817) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 77356 + ... + 80522.

It is an arithmetic number, because the mean of its divisors is an integer number (11737440).

Almost surely, 2^249999813 is an apocalyptic number.

It is an amenable number.

249999813 is a deficient number, since it is larger than the sum of its proper divisors (172548027).

249999813 is a wasteful number, since it uses less digits than its factorization.

249999813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3366 (or 3356 counting only the distinct ones).

The product of its digits is 1259712, while the sum is 54.

The square root of 249999813 is about 15811.3823873816. The cubic root of 249999813 is about 629.9603678772.

The spelling of 249999813 in words is "two hundred forty-nine million, nine hundred ninety-nine thousand, eight hundred thirteen".