21276533 has 4 divisors (see below), whose sum is σ = 21323148. Its totient is φ = 21229920.

The previous prime is 21276491. The next prime is 21276547. The reversal of 21276533 is 33567212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14190289 + 7086244 = 3767^2 + 2662^2 .

It is a cyclic number.

It is not a de Polignac number, because 21276533 - 2¹⁰ = 21275509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21276496 and 21276505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21276583) 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 3 ways as a sum of consecutive naturals, for example, 22616 + ... + 23537.

It is an arithmetic number, because the mean of its divisors is an integer number (5330787).

Almost surely, 2^21276533 is an apocalyptic number.

It is an amenable number.

21276533 is a deficient number, since it is larger than the sum of its proper divisors (46615).

21276533 is an equidigital number, since it uses as much as digits as its factorization.

21276533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46614.

The product of its digits is 7560, while the sum is 29.

The square root of 21276533 is about 4612.6492387781. The cubic root of 21276533 is about 277.0981462649.

The spelling of 21276533 in words is "twenty-one million, two hundred seventy-six thousand, five hundred thirty-three".