21101445 has 16 divisors (see below), whose sum is σ = 37513920. Its totient is φ = 11254032.

The previous prime is 21101441. The next prime is 21101459. The reversal of 21101445 is 54410112.

It is not a de Polignac number, because 21101445 - 2² = 21101441 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 78019 + ... + 78288.

It is an arithmetic number, because the mean of its divisors is an integer number (2344620).

Almost surely, 2^21101445 is an apocalyptic number.

It is an amenable number.

21101445 is a deficient number, since it is larger than the sum of its proper divisors (16412475).

21101445 is a wasteful number, since it uses less digits than its factorization.

21101445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156321 (or 156315 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 21101445 is about 4593.6309168239. The cubic root of 21101445 is about 276.3359566806.

Adding to 21101445 its reverse (54410112), we get a palindrome (75511557).

The spelling of 21101445 in words is "twenty-one million, one hundred one thousand, four hundred forty-five".