100722721 has 4 divisors (see below), whose sum is σ = 109879344. Its totient is φ = 91566100.

The previous prime is 100722719. The next prime is 100722733. The reversal of 100722721 is 127227001.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 100722721 - 2¹ = 100722719 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 100722692 and 100722701.

It is not an unprimeable number, because it can be changed into a prime (100722701) 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, 4578295 + ... + 4578316.

It is an arithmetic number, because the mean of its divisors is an integer number (27469836).

Almost surely, 2^100722721 is an apocalyptic number.

100722721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

100722721 is a deficient number, since it is larger than the sum of its proper divisors (9156623).

100722721 is an equidigital number, since it uses as much as digits as its factorization.

100722721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9156622.

The product of its (nonzero) digits is 392, while the sum is 22.

The square root of 100722721 is about 10036.0709941690. The cubic root of 100722721 is about 465.2743915655.

Adding to 100722721 its reverse (127227001), we get a palindrome (227949722).

The spelling of 100722721 in words is "one hundred million, seven hundred twenty-two thousand, seven hundred twenty-one".