249749989 has 2 divisors, whose sum is σ = 249749990. Its totient is φ = 249749988.

The previous prime is 249749957. The next prime is 249750019. The reversal of 249749989 is 989947942.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 157301764 + 92448225 = 12542^2 + 9615^2 .

It is a cyclic number.

It is not a de Polignac number, because 249749989 - 2⁵ = 249749957 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (249749909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124874994 + 124874995.

It is an arithmetic number, because the mean of its divisors is an integer number (124874995).

Almost surely, 2^249749989 is an apocalyptic number.

It is an amenable number.

249749989 is a deficient number, since it is larger than the sum of its proper divisors (1).

249749989 is an equidigital number, since it uses as much as digits as its factorization.

249749989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11757312, while the sum is 61.

The square root of 249749989 is about 15803.4802812545. The cubic root of 249749989 is about 629.7504588257.

The spelling of 249749989 in words is "two hundred forty-nine million, seven hundred forty-nine thousand, nine hundred eighty-nine".