100445921 has 4 divisors (see below), whose sum is σ = 103686144. Its totient is φ = 97205700.

The previous prime is 100445903. The next prime is 100445959. The reversal of 100445921 is 129544001.

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, and also an emirpimes, since its reverse is a distinct semiprime: 129544001 = 577 ⋅224513.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-100445921 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (100445981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1620065 + ... + 1620126.

It is an arithmetic number, because the mean of its divisors is an integer number (25921536).

Almost surely, 2^100445921 is an apocalyptic number.

It is an amenable number.

100445921 is a deficient number, since it is larger than the sum of its proper divisors (3240223).

100445921 is an equidigital number, since it uses as much as digits as its factorization.

100445921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3240222.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 100445921 is about 10022.2712495721. The cubic root of 100445921 is about 464.8477876955.

Adding to 100445921 its reverse (129544001), we get a palindrome (229989922).

The spelling of 100445921 in words is "one hundred million, four hundred forty-five thousand, nine hundred twenty-one".