21628535 has 8 divisors (see below), whose sum is σ = 26655936. Its totient is φ = 16835040.

The previous prime is 21628501. The next prime is 21628553. The reversal of 21628535 is 53582612.

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

It is not a de Polignac number, because 21628535 - 2¹⁸ = 21366391 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 58271 + ... + 58640.

It is an arithmetic number, because the mean of its divisors is an integer number (3331992).

Almost surely, 2^21628535 is an apocalyptic number.

21628535 is a deficient number, since it is larger than the sum of its proper divisors (5027401).

21628535 is a wasteful number, since it uses less digits than its factorization.

21628535 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116953.

The product of its digits is 14400, while the sum is 32.

The square root of 21628535 is about 4650.6488794576. The cubic root of 21628535 is about 278.6179128465.

The spelling of 21628535 in words is "twenty-one million, six hundred twenty-eight thousand, five hundred thirty-five".