21435736 has 48 divisors (see below), whose sum is σ = 47196000. Its totient is φ = 9100224.

The previous prime is 21435731. The next prime is 21435737. The reversal of 21435736 is 63753412.

It is a junction number, because it is equal to n+sod(n) for n = 21435698 and 21435707.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21435731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 58225 + ... + 58591.

It is an arithmetic number, because the mean of its divisors is an integer number (983250).

Almost surely, 2^21435736 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 21435736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23598000).

21435736 is an abundant number, since it is smaller than the sum of its proper divisors (25760264).

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

21435736 is a wasteful number, since it uses less digits than its factorization.

21435736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 536 (or 525 counting only the distinct ones).

The product of its digits is 15120, while the sum is 31.

The square root of 21435736 is about 4629.8742963497. The cubic root of 21435736 is about 277.7875643604.

The spelling of 21435736 in words is "twenty-one million, four hundred thirty-five thousand, seven hundred thirty-six".