249972217 has 4 divisors (see below), whose sum is σ = 272696976. Its totient is φ = 227247460.

The previous prime is 249972209. The next prime is 249972263. The reversal of 249972217 is 712279942.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 249972217 - 2³ = 249972209 is a prime.

It is a super-2 number, since 2×249972217² = 124972218543790178, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (249972017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11362363 + ... + 11362384.

It is an arithmetic number, because the mean of its divisors is an integer number (68174244).

Almost surely, 2^249972217 is an apocalyptic number.

It is an amenable number.

249972217 is a deficient number, since it is larger than the sum of its proper divisors (22724759).

249972217 is a wasteful number, since it uses less digits than its factorization.

249972217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22724758.

The product of its digits is 127008, while the sum is 43.

The square root of 249972217 is about 15810.5097008287. The cubic root of 249972217 is about 629.9371878252.

The spelling of 249972217 in words is "two hundred forty-nine million, nine hundred seventy-two thousand, two hundred seventeen".