100721297 has 4 divisors (see below), whose sum is σ = 103177956. Its totient is φ = 98264640.

The previous prime is 100721281. The next prime is 100721317. The reversal of 100721297 is 792127001.

It is a Cunningham number, because it is equal to 10036²+1.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 792127001 = 131 ⋅6046771.

It can be written as a sum of positive squares in 2 ways, for example, as 4857616 + 95863681 = 2204^2 + 9791^2 .

It is a cyclic number.

It is not a de Polignac number, because 100721297 - 2⁴ = 100721281 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (100721237) 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, 1228268 + ... + 1228349.

It is an arithmetic number, because the mean of its divisors is an integer number (25794489).

Almost surely, 2^100721297 is an apocalyptic number.

It is an amenable number.

100721297 is a deficient number, since it is larger than the sum of its proper divisors (2456659).

100721297 is an equidigital number, since it uses as much as digits as its factorization.

100721297 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2456658.

The product of its (nonzero) digits is 1764, while the sum is 29.

The square root of 100721297 is about 10036.0000498206. Note that the first 4 decimals coincide. The cubic root of 100721297 is about 465.2721988995.

Adding to 100721297 its reverse (792127001), we get a palindrome (892848298).

The spelling of 100721297 in words is "one hundred million, seven hundred twenty-one thousand, two hundred ninety-seven".