21533454 has 36 divisors (see below), whose sum is σ = 47839896. Its totient is φ = 7000056.

The previous prime is 21533443. The next prime is 21533459. The reversal of 21533454 is 45433512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21533459) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 32959 + ... + 33605.

It is an arithmetic number, because the mean of its divisors is an integer number (1328886).

Almost surely, 2^21533454 is an apocalyptic number.

21533454 is an abundant number, since it is smaller than the sum of its proper divisors (26306442).

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

21533454 is a wasteful number, since it uses less digits than its factorization.

21533454 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 741 (or 695 counting only the distinct ones).

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

The square root of 21533454 is about 4640.4152831401. The cubic root of 21533454 is about 278.2090365757.

Adding to 21533454 its reverse (45433512), we get a palindrome (66966966).

The spelling of 21533454 in words is "twenty-one million, five hundred thirty-three thousand, four hundred fifty-four".