249712681 has 2 divisors, whose sum is σ = 249712682. Its totient is φ = 249712680.

The previous prime is 249712663. The next prime is 249712693. The reversal of 249712681 is 186217942.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 244609600 + 5103081 = 15640^2 + 2259^2 .

It is a cyclic number.

It is not a de Polignac number, because 249712681 - 2¹¹ = 249710633 is a prime.

It is a super-2 number, since 2×249712681² = 124712846104415522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (249812681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124856340 + 124856341.

It is an arithmetic number, because the mean of its divisors is an integer number (124856341).

Almost surely, 2^249712681 is an apocalyptic number.

It is an amenable number.

249712681 is a deficient number, since it is larger than the sum of its proper divisors (1).

249712681 is an equidigital number, since it uses as much as digits as its factorization.

249712681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48384, while the sum is 40.

The square root of 249712681 is about 15802.2998642603. The cubic root of 249712681 is about 629.7190995983.

The spelling of 249712681 in words is "two hundred forty-nine million, seven hundred twelve thousand, six hundred eighty-one".