21100045 has 8 divisors (see below), whose sum is σ = 25363296. Its totient is φ = 16851216.

The previous prime is 21100033. The next prime is 21100049. The reversal of 21100045 is 54000112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21100045 - 2⁷ = 21099917 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21099998 and 21100034.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100049) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67 + ... + 6496.

It is an arithmetic number, because the mean of its divisors is an integer number (3170412).

Almost surely, 2^21100045 is an apocalyptic number.

It is an amenable number.

21100045 is a deficient number, since it is larger than the sum of its proper divisors (4263251).

21100045 is an equidigital number, since it uses as much as digits as its factorization.

21100045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7211.

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 21100045 is about 4593.4785293936. The cubic root of 21100045 is about 276.3298452682.

Adding to 21100045 its reverse (54000112), we get a palindrome (75100157).

The spelling of 21100045 in words is "twenty-one million, one hundred thousand, forty-five".