21945753 has 6 divisors (see below), whose sum is σ = 31699434. Its totient is φ = 14630496.

The previous prime is 21945751. The next prime is 21945769. The reversal of 21945753 is 35754912.

It can be written as a sum of positive squares in only one way, i.e., 19474569 + 2471184 = 4413^2 + 1572^2 .

It is not a de Polignac number, because 21945753 - 2¹ = 21945751 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21945751) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1219200 + ... + 1219217.

It is an arithmetic number, because the mean of its divisors is an integer number (5283239).

Almost surely, 2^21945753 is an apocalyptic number.

It is an amenable number.

21945753 is a deficient number, since it is larger than the sum of its proper divisors (9753681).

21945753 is a wasteful number, since it uses less digits than its factorization.

21945753 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2438423 (or 2438420 counting only the distinct ones).

The product of its digits is 37800, while the sum is 36.

The square root of 21945753 is about 4684.6294410551. The cubic root of 21945753 is about 279.9734371060.

The spelling of 21945753 in words is "twenty-one million, nine hundred forty-five thousand, seven hundred fifty-three".