21036534 has 32 divisors (see below), whose sum is σ = 44666880. Its totient is φ = 6586272.

The previous prime is 21036527. The next prime is 21036539. The reversal of 21036534 is 43563012.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21036539) 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, 13752 + ... + 15204.

It is an arithmetic number, because the mean of its divisors is an integer number (1395840).

Almost surely, 2^21036534 is an apocalyptic number.

21036534 is an abundant number, since it is smaller than the sum of its proper divisors (23630346).

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

21036534 is a wasteful number, since it uses less digits than its factorization.

21036534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1604.

The product of its (nonzero) digits is 2160, while the sum is 24.

The square root of 21036534 is about 4586.5601489570. The cubic root of 21036534 is about 276.0523162747.

Adding to 21036534 its reverse (43563012), we get a palindrome (64599546).

The spelling of 21036534 in words is "twenty-one million, thirty-six thousand, five hundred thirty-four".