21045827 has 8 divisors (see below), whose sum is σ = 23274480. Its totient is φ = 18869760.

The previous prime is 21045811. The next prime is 21045853. The reversal of 21045827 is 72854012.

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 21045827 - 2⁴ = 21045811 is a prime.

It is a super-2 number, since 2×21045827² = 885853668227858, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21045827.

It is not an unprimeable number, because it can be changed into a prime (21045127) 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, 12302 + ... + 13907.

It is an arithmetic number, because the mean of its divisors is an integer number (2909310).

Almost surely, 2^21045827 is an apocalyptic number.

21045827 is a deficient number, since it is larger than the sum of its proper divisors (2228653).

21045827 is a wasteful number, since it uses less digits than its factorization.

21045827 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26293.

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

The square root of 21045827 is about 4587.5731056845. The cubic root of 21045827 is about 276.0929594801.

Adding to 21045827 its reverse (72854012), we get a palindrome (93899839).

The spelling of 21045827 in words is "twenty-one million, forty-five thousand, eight hundred twenty-seven".