21995533 has 4 divisors (see below), whose sum is σ = 25137760. Its totient is φ = 18853308.

The previous prime is 21995531. The next prime is 21995537. The reversal of 21995533 is 33559912.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21995533 - 2¹ = 21995531 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21995492 and 21995501.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21995531) 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 3 ways as a sum of consecutive naturals, for example, 1571103 + ... + 1571116.

It is an arithmetic number, because the mean of its divisors is an integer number (6284440).

Almost surely, 2^21995533 is an apocalyptic number.

It is an amenable number.

21995533 is a deficient number, since it is larger than the sum of its proper divisors (3142227).

21995533 is an equidigital number, since it uses as much as digits as its factorization.

21995533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3142226.

The product of its digits is 36450, while the sum is 37.

The square root of 21995533 is about 4689.9395518493. The cubic root of 21995533 is about 280.1849670702.

The spelling of 21995533 in words is "twenty-one million, nine hundred ninety-five thousand, five hundred thirty-three".