21908753 has 2 divisors, whose sum is σ = 21908754. Its totient is φ = 21908752.

The previous prime is 21908743. The next prime is 21908771. The reversal of 21908753 is 35780912.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21836929 + 71824 = 4673^2 + 268^2 .

It is a cyclic number.

It is not a de Polignac number, because 21908753 - 2¹⁰ = 21907729 is a prime.

It is not a weakly prime, because it can be changed into another prime (21908713) 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 as a sum of consecutive naturals, namely, 10954376 + 10954377.

It is an arithmetic number, because the mean of its divisors is an integer number (10954377).

Almost surely, 2^21908753 is an apocalyptic number.

It is an amenable number.

21908753 is a deficient number, since it is larger than the sum of its proper divisors (1).

21908753 is an equidigital number, since it uses as much as digits as its factorization.

21908753 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 21908753 is about 4680.6786901047. The cubic root of 21908753 is about 279.8160058205.

It can be divided in two parts, 219087 and 53, that multiplied together give a palindrome (11611611).

The spelling of 21908753 in words is "twenty-one million, nine hundred eight thousand, seven hundred fifty-three".