21536736 has 48 divisors (see below), whose sum is σ = 60886224. Its totient is φ = 6626304.

The previous prime is 21536707. The next prime is 21536737. The reversal of 21536736 is 63763512.

It is a tau number, because it is divible by the number of its divisors (48).

It is a junction number, because it is equal to n+sod(n) for n = 21536697 and 21536706.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21536737) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7381 + ... + 9876.

It is an arithmetic number, because the mean of its divisors is an integer number (1268463).

Almost surely, 2^21536736 is an apocalyptic number.

21536736 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21536736 is an abundant number, since it is smaller than the sum of its proper divisors (39349488).

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

21536736 is a wasteful number, since it uses less digits than its factorization.

21536736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17283 (or 17275 counting only the distinct ones).

The product of its digits is 22680, while the sum is 33.

The square root of 21536736 is about 4640.7689018093. The cubic root of 21536736 is about 278.2231701757.

The spelling of 21536736 in words is "twenty-one million, five hundred thirty-six thousand, seven hundred thirty-six".