249545139 has 4 divisors (see below), whose sum is σ = 332726856. Its totient is φ = 166363424.

The previous prime is 249545123. The next prime is 249545143. The reversal of 249545139 is 931545942.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 249545139 - 2⁴ = 249545123 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 249545139.

It is not an unprimeable number, because it can be changed into a prime (249545189) 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, 41590854 + ... + 41590859.

It is an arithmetic number, because the mean of its divisors is an integer number (83181714).

Almost surely, 2^249545139 is an apocalyptic number.

249545139 is a deficient number, since it is larger than the sum of its proper divisors (83181717).

249545139 is an equidigital number, since it uses as much as digits as its factorization.

249545139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83181716.

The product of its digits is 194400, while the sum is 42.

The square root of 249545139 is about 15796.9977843893. The cubic root of 249545139 is about 629.5782337020.

The spelling of 249545139 in words is "two hundred forty-nine million, five hundred forty-five thousand, one hundred thirty-nine".