99987257 has 2 divisors, whose sum is σ = 99987258. Its totient is φ = 99987256.

The previous prime is 99987221. The next prime is 99987263. The reversal of 99987257 is 75278999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 85729081 + 14258176 = 9259^2 + 3776^2 .

It is a cyclic number.

It is not a de Polignac number, because 99987257 - 2¹⁰ = 99986233 is a prime.

It is not a weakly prime, because it can be changed into another prime (99987457) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49993628 + 49993629.

It is an arithmetic number, because the mean of its divisors is an integer number (49993629).

Almost surely, 2^99987257 is an apocalyptic number.

It is an amenable number.

99987257 is a deficient number, since it is larger than the sum of its proper divisors (1).

99987257 is an equidigital number, since it uses as much as digits as its factorization.

99987257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2857680, while the sum is 56.

The square root of 99987257 is about 9999.3628297007. The cubic root of 99987257 is about 464.1391666016.

The spelling of 99987257 in words is "ninety-nine million, nine hundred eighty-seven thousand, two hundred fifty-seven".