99680257 has 4 divisors (see below), whose sum is σ = 102374356. Its totient is φ = 96986160.

The previous prime is 99680249. The next prime is 99680281. The reversal of 99680257 is 75208699.

It is a Cunningham number, because it is equal to 9984²+1.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 89189136 + 10491121 = 9444^2 + 3239^2 .

It is a cyclic number.

It is not a de Polignac number, because 99680257 - 2³ = 99680249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99680557) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1346994 + ... + 1347067.

It is an arithmetic number, because the mean of its divisors is an integer number (25593589).

It is a Proth number, since it is equal to 1521 ⋅ 2¹⁶ + 1 and 1521 < 2¹⁶.

Almost surely, 2^99680257 is an apocalyptic number.

It is an amenable number.

99680257 is a deficient number, since it is larger than the sum of its proper divisors (2694099).

99680257 is a wasteful number, since it uses less digits than its factorization.

99680257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2694098.

The product of its (nonzero) digits is 272160, while the sum is 46.

The square root of 99680257 is about 9984.0000500801. Note that the first 4 decimals coincide. The cubic root of 99680257 is about 463.6636499815.

The spelling of 99680257 in words is "ninety-nine million, six hundred eighty thousand, two hundred fifty-seven".