21284045 has 8 divisors (see below), whose sum is σ = 25670400. Its totient is φ = 16940880.

The previous prime is 21284041. The next prime is 21284093. The reversal of 21284045 is 54048212.

It is a happy number.

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

It is not a de Polignac number, because 21284045 - 2² = 21284041 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21284041) 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 7 ways as a sum of consecutive naturals, for example, 9701 + ... + 11690.

It is an arithmetic number, because the mean of its divisors is an integer number (3208800).

Almost surely, 2^21284045 is an apocalyptic number.

It is an amenable number.

21284045 is a deficient number, since it is larger than the sum of its proper divisors (4386355).

21284045 is a wasteful number, since it uses less digits than its factorization.

21284045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21595.

The product of its (nonzero) digits is 2560, while the sum is 26.

The square root of 21284045 is about 4613.4634495138. The cubic root of 21284045 is about 277.1307536505.

The spelling of 21284045 in words is "twenty-one million, two hundred eighty-four thousand, forty-five".