249129217 has 4 divisors (see below), whose sum is σ = 252542020. Its totient is φ = 245716416.

The previous prime is 249129191. The next prime is 249129269. The reversal of 249129217 is 712921942.

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

It can be written as a sum of positive squares in 2 ways, for example, as 130667761 + 118461456 = 11431^2 + 10884^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-249129217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (249129017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1706292 + ... + 1706437.

It is an arithmetic number, because the mean of its divisors is an integer number (63135505).

Almost surely, 2^249129217 is an apocalyptic number.

It is an amenable number.

249129217 is a deficient number, since it is larger than the sum of its proper divisors (3412803).

249129217 is an equidigital number, since it uses as much as digits as its factorization.

249129217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3412802.

The product of its digits is 18144, while the sum is 37.

The square root of 249129217 is about 15783.8277043308. The cubic root of 249129217 is about 629.2282622112.

The spelling of 249129217 in words is "two hundred forty-nine million, one hundred twenty-nine thousand, two hundred seventeen".