21114545 has 4 divisors (see below), whose sum is σ = 25337460. Its totient is φ = 16891632.

The previous prime is 21114521. The next prime is 21114547. The reversal of 21114545 is 54541112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16128256 + 4986289 = 4016^2 + 2233^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21114545 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21114545.

It is not an unprimeable number, because it can be changed into a prime (21114547) 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, 2111450 + ... + 2111459.

It is an arithmetic number, because the mean of its divisors is an integer number (6334365).

Almost surely, 2^21114545 is an apocalyptic number.

It is an amenable number.

21114545 is a deficient number, since it is larger than the sum of its proper divisors (4222915).

21114545 is an equidigital number, since it uses as much as digits as its factorization.

21114545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4222914.

The product of its digits is 800, while the sum is 23.

The square root of 21114545 is about 4595.0565828943. The cubic root of 21114545 is about 276.3931289450.

Adding to 21114545 its reverse (54541112), we get a palindrome (75655657).

The spelling of 21114545 in words is "twenty-one million, one hundred fourteen thousand, five hundred forty-five".