249947681 has 2 divisors, whose sum is σ = 249947682. Its totient is φ = 249947680.

The previous prime is 249947669. The next prime is 249947701. The reversal of 249947681 is 186749942.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 249166225 + 781456 = 15785^2 + 884^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-249947681 is a prime.

It is a super-2 number, since 2×249947681² = 124947686474555522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (249947281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124973840 + 124973841.

It is an arithmetic number, because the mean of its divisors is an integer number (124973841).

Almost surely, 2^249947681 is an apocalyptic number.

It is an amenable number.

249947681 is a deficient number, since it is larger than the sum of its proper divisors (1).

249947681 is an equidigital number, since it uses as much as digits as its factorization.

249947681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 870912, while the sum is 50.

The square root of 249947681 is about 15809.7337422235. The cubic root of 249947681 is about 629.9165766752.

The spelling of 249947681 in words is "two hundred forty-nine million, nine hundred forty-seven thousand, six hundred eighty-one".