21827045 has 4 divisors (see below), whose sum is σ = 26192460. Its totient is φ = 17461632.

The previous prime is 21827041. The next prime is 21827051. The reversal of 21827045 is 54072812.

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 2660161 + 19166884 = 1631^2 + 4378^2 .

It is a cyclic number.

It is not a de Polignac number, because 21827045 - 2² = 21827041 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21826999 and 21827017.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21827041) 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 3 ways as a sum of consecutive naturals, for example, 2182700 + ... + 2182709.

It is an arithmetic number, because the mean of its divisors is an integer number (6548115).

Almost surely, 2^21827045 is an apocalyptic number.

It is an amenable number.

21827045 is a deficient number, since it is larger than the sum of its proper divisors (4365415).

21827045 is an equidigital number, since it uses as much as digits as its factorization.

21827045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4365414.

The product of its (nonzero) digits is 4480, while the sum is 29.

The square root of 21827045 is about 4671.9423155685. The cubic root of 21827045 is about 279.4677175089.

Adding to 21827045 its reverse (54072812), we get a palindrome (75899857).

The spelling of 21827045 in words is "twenty-one million, eight hundred twenty-seven thousand, forty-five".