21628735 has 8 divisors (see below), whose sum is σ = 26159616. Its totient is φ = 17166240.

The previous prime is 21628729. The next prime is 21628741. The reversal of 21628735 is 53782612.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21628729) and next prime (21628741).

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

It is not a de Polignac number, because 21628735 - 2⁵ = 21628703 is a prime.

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 21628735.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 16396 + ... + 17665.

It is an arithmetic number, because the mean of its divisors is an integer number (3269952).

Almost surely, 2^21628735 is an apocalyptic number.

21628735 is a deficient number, since it is larger than the sum of its proper divisors (4530881).

21628735 is a wasteful number, since it uses less digits than its factorization.

21628735 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34193.

The product of its digits is 20160, while the sum is 34.

The square root of 21628735 is about 4650.6703817837. The cubic root of 21628735 is about 278.6187716412.

The spelling of 21628735 in words is "twenty-one million, six hundred twenty-eight thousand, seven hundred thirty-five".