249987217 has 2 divisors, whose sum is σ = 249987218. Its totient is φ = 249987216.

The previous prime is 249987109. The next prime is 249987223. The reversal of 249987217 is 712789942.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 184117761 + 65869456 = 13569^2 + 8116^2 .

It is a cyclic number.

It is not a de Polignac number, because 249987217 - 2¹⁵ = 249954449 is a prime.

It is a super-4 number, since 4×249987217⁴ (a number of 35 digits) contains 4444 as substring.

It is not a weakly prime, because it can be changed into another prime (249987247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124993608 + 124993609.

It is an arithmetic number, because the mean of its divisors is an integer number (124993609).

Almost surely, 2^249987217 is an apocalyptic number.

It is an amenable number.

249987217 is a deficient number, since it is larger than the sum of its proper divisors (1).

249987217 is an equidigital number, since it uses as much as digits as its factorization.

249987217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 508032, while the sum is 49.

The square root of 249987217 is about 15810.9840617211. The cubic root of 249987217 is about 629.9497877172.

The spelling of 249987217 in words is "two hundred forty-nine million, nine hundred eighty-seven thousand, two hundred seventeen".