100721249 has 4 divisors (see below), whose sum is σ = 100864020. Its totient is φ = 100578480.

The previous prime is 100721237. The next prime is 100721267. The reversal of 100721249 is 942127001.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 942127001 = 409 ⋅2303489.

It can be written as a sum of positive squares in 2 ways, for example, as 43824400 + 56896849 = 6620^2 + 7543^2 .

It is a cyclic number.

It is not a de Polignac number, because 100721249 - 2⁴ = 100721233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (100721219) 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, 70322 + ... + 71739.

It is an arithmetic number, because the mean of its divisors is an integer number (25216005).

Almost surely, 2^100721249 is an apocalyptic number.

It is an amenable number.

100721249 is a deficient number, since it is larger than the sum of its proper divisors (142771).

100721249 is an equidigital number, since it uses as much as digits as its factorization.

100721249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142770.

The product of its (nonzero) digits is 1008, while the sum is 26.

The square root of 100721249 is about 10035.9976584294. The cubic root of 100721249 is about 465.2721249891.

The spelling of 100721249 in words is "one hundred million, seven hundred twenty-one thousand, two hundred forty-nine".