21850753 has 4 divisors (see below), whose sum is σ = 22555648. Its totient is φ = 21145860.

The previous prime is 21850733. The next prime is 21850769. The reversal of 21850753 is 35705812.

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 21850753 - 2⁵ = 21850721 is a prime.

It is a super-3 number, since 3×21850753³ (a number of 23 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 704863 = 21850753 / (2 + 1 + 8 + 5 + 0 + 7 + 5 + 3).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21850733) 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, 352401 + ... + 352462.

It is an arithmetic number, because the mean of its divisors is an integer number (5638912).

Almost surely, 2^21850753 is an apocalyptic number.

It is an amenable number.

21850753 is a deficient number, since it is larger than the sum of its proper divisors (704895).

21850753 is an equidigital number, since it uses as much as digits as its factorization.

21850753 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 704894.

The product of its (nonzero) digits is 8400, while the sum is 31.

The square root of 21850753 is about 4674.4789014392. The cubic root of 21850753 is about 279.5688645528.

The spelling of 21850753 in words is "twenty-one million, eight hundred fifty thousand, seven hundred fifty-three".