21748733 has 4 divisors (see below), whose sum is σ = 22211520. Its totient is φ = 21285948.

The previous prime is 21748717. The next prime is 21748747. The reversal of 21748733 is 33784712.

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 21748733 - 2⁴ = 21748717 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21748693 and 21748702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21748033) 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, 231323 + ... + 231416.

It is an arithmetic number, because the mean of its divisors is an integer number (5552880).

Almost surely, 2^21748733 is an apocalyptic number.

It is an amenable number.

21748733 is a deficient number, since it is larger than the sum of its proper divisors (462787).

21748733 is an equidigital number, since it uses as much as digits as its factorization.

21748733 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 462786.

The product of its digits is 28224, while the sum is 35.

The square root of 21748733 is about 4663.5536879080. The cubic root of 21748733 is about 279.1330882709.

The spelling of 21748733 in words is "twenty-one million, seven hundred forty-eight thousand, seven hundred thirty-three".