21433545 has 64 divisors (see below), whose sum is σ = 44797440. Its totient is φ = 9517824.

The previous prime is 21433541. The next prime is 21433553. The reversal of 21433545 is 54533412.

It is not a de Polignac number, because 21433545 - 2² = 21433541 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21433541) 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 63 ways as a sum of consecutive naturals, for example, 34659 + ... + 35271.

It is an arithmetic number, because the mean of its divisors is an integer number (699960).

Almost surely, 2^21433545 is an apocalyptic number.

It is an amenable number.

21433545 is an abundant number, since it is smaller than the sum of its proper divisors (23363895).

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

21433545 is a wasteful number, since it uses less digits than its factorization.

21433545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 671 (or 665 counting only the distinct ones).

The product of its digits is 7200, while the sum is 27.

The square root of 21433545 is about 4629.6376748078. The cubic root of 21433545 is about 277.7780995848.

Adding to 21433545 its reverse (54533412), we get a palindrome (75966957).

The spelling of 21433545 in words is "twenty-one million, four hundred thirty-three thousand, five hundred forty-five".