249875981 has 2 divisors, whose sum is σ = 249875982. Its totient is φ = 249875980.

The previous prime is 249875971. The next prime is 249875993. The reversal of 249875981 is 189578942.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 206381956 + 43494025 = 14366^2 + 6595^2 .

It is a cyclic number.

It is not a de Polignac number, because 249875981 - 2¹⁰ = 249874957 is a prime.

It is a super-2 number, since 2×249875981² = 124876011761424722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (249875971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124937990 + 124937991.

It is an arithmetic number, because the mean of its divisors is an integer number (124937991).

Almost surely, 2^249875981 is an apocalyptic number.

It is an amenable number.

249875981 is a deficient number, since it is larger than the sum of its proper divisors (1).

249875981 is an equidigital number, since it uses as much as digits as its factorization.

249875981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1451520, while the sum is 53.

The square root of 249875981 is about 15807.4659892090. The cubic root of 249875981 is about 629.8563382849.

The spelling of 249875981 in words is "two hundred forty-nine million, eight hundred seventy-five thousand, nine hundred eighty-one".