21453736 has 64 divisors (see below), whose sum is σ = 45504000. Its totient is φ = 9434880.

The previous prime is 21453727. The next prime is 21453737. The reversal of 21453736 is 63735412.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a plaindrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 21453698 and 21453707.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21453737) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 136570 + ... + 136726.

It is an arithmetic number, because the mean of its divisors is an integer number (711000).

Almost surely, 2^21453736 is an apocalyptic number.

It is an amenable number.

21453736 is an abundant number, since it is smaller than the sum of its proper divisors (24050264).

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

21453736 is a wasteful number, since it uses less digits than its factorization.

21453736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242 (or 238 counting only the distinct ones).

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

The square root of 21453736 is about 4631.8177857079. The cubic root of 21453736 is about 277.8652971276.

The spelling of 21453736 in words is "twenty-one million, four hundred fifty-three thousand, seven hundred thirty-six".