100721447 has 4 divisors (see below), whose sum is σ = 106646256. Its totient is φ = 94796640.

The previous prime is 100721377. The next prime is 100721459. The reversal of 100721447 is 744127001.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 744127001 = 19 ⋅39164579.

It is a cyclic number.

It is not a de Polignac number, because 100721447 - 2⁸ = 100721191 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (100721497) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2962379 + ... + 2962412.

It is an arithmetic number, because the mean of its divisors is an integer number (26661564).

Almost surely, 2^100721447 is an apocalyptic number.

100721447 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

100721447 is a deficient number, since it is larger than the sum of its proper divisors (5924809).

100721447 is an equidigital number, since it uses as much as digits as its factorization.

100721447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5924808.

The product of its (nonzero) digits is 1568, while the sum is 26.

The square root of 100721447 is about 10036.0075229147. The cubic root of 100721447 is about 465.2724298695.

Adding to 100721447 its reverse (744127001), we get a palindrome (844848448).

The spelling of 100721447 in words is "one hundred million, seven hundred twenty-one thousand, four hundred forty-seven".