21333436 has 12 divisors (see below), whose sum is σ = 39529728. Its totient is φ = 10039232.

The previous prime is 21333413. The next prime is 21333437. The reversal of 21333436 is 63433312.

It is a self number, because there is not a number n which added to its sum of digits gives 21333436.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21333437) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 156796 + ... + 156931.

It is an arithmetic number, because the mean of its divisors is an integer number (3294144).

Almost surely, 2^21333436 is an apocalyptic number.

It is an amenable number.

21333436 is a deficient number, since it is larger than the sum of its proper divisors (18196292).

21333436 is a wasteful number, since it uses less digits than its factorization.

21333436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 313748 (or 313746 counting only the distinct ones).

The product of its digits is 3888, while the sum is 25.

The square root of 21333436 is about 4618.8132674963. The cubic root of 21333436 is about 277.3449546464.

Adding to 21333436 its reverse (63433312), we get a palindrome (84766748).

The spelling of 21333436 in words is "twenty-one million, three hundred thirty-three thousand, four hundred thirty-six".