249640537 has 2 divisors, whose sum is σ = 249640538. Its totient is φ = 249640536.

The previous prime is 249640507. The next prime is 249640561. The reversal of 249640537 is 735046942.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 216796176 + 32844361 = 14724^2 + 5731^2 .

It is a cyclic number.

It is not a de Polignac number, because 249640537 - 2²³ = 241251929 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 249640537.

It is not a weakly prime, because it can be changed into another prime (249640507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124820268 + 124820269.

It is an arithmetic number, because the mean of its divisors is an integer number (124820269).

Almost surely, 2^249640537 is an apocalyptic number.

It is an amenable number.

249640537 is a deficient number, since it is larger than the sum of its proper divisors (1).

249640537 is an equidigital number, since it uses as much as digits as its factorization.

249640537 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 181440, while the sum is 40.

The square root of 249640537 is about 15800.0169936617. The cubic root of 249640537 is about 629.6584501213.

The spelling of 249640537 in words is "two hundred forty-nine million, six hundred forty thousand, five hundred thirty-seven".