21282645 has 16 divisors (see below), whose sum is σ = 34125120. Its totient is φ = 11326464.

The previous prime is 21282643. The next prime is 21282661. The reversal of 21282645 is 54628212.

It is not a de Polignac number, because 21282645 - 2¹ = 21282643 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21282643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7426 + ... + 9884.

It is an arithmetic number, because the mean of its divisors is an integer number (2132820).

Almost surely, 2^21282645 is an apocalyptic number.

It is an amenable number.

21282645 is a deficient number, since it is larger than the sum of its proper divisors (12842475).

21282645 is a wasteful number, since it uses less digits than its factorization.

21282645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3044.

The product of its digits is 7680, while the sum is 30.

The square root of 21282645 is about 4613.3117171941. The cubic root of 21282645 is about 277.1246772435.

The spelling of 21282645 in words is "twenty-one million, two hundred eighty-two thousand, six hundred forty-five".