21535136 has 48 divisors (see below), whose sum is σ = 48900096. Its totient is φ = 9144576.

The previous prime is 21535123. The next prime is 21535169. The reversal of 21535136 is 63153512.

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, 28070 + ... + 28826.

It is an arithmetic number, because the mean of its divisors is an integer number (1018752).

Almost surely, 2^21535136 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21535136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24450048).

21535136 is an abundant number, since it is smaller than the sum of its proper divisors (27364960).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21535136 is a wasteful number, since it uses less digits than its factorization.

21535136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 901 (or 893 counting only the distinct ones).

The product of its digits is 2700, while the sum is 26.

The square root of 21535136 is about 4640.5965133806. The cubic root of 21535136 is about 278.2162801174.

Adding to 21535136 its reverse (63153512), we get a palindrome (84688648).

The spelling of 21535136 in words is "twenty-one million, five hundred thirty-five thousand, one hundred thirty-six".