21653153 has 2 divisors, whose sum is σ = 21653154. Its totient is φ = 21653152.

The previous prime is 21653131. The next prime is 21653167. The reversal of 21653153 is 35135612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20857489 + 795664 = 4567^2 + 892^2 .

It is a cyclic number.

It is not a de Polignac number, because 21653153 - 2⁶ = 21653089 is a prime.

It is not a weakly prime, because it can be changed into another prime (21653183) 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, 10826576 + 10826577.

It is an arithmetic number, because the mean of its divisors is an integer number (10826577).

Almost surely, 2^21653153 is an apocalyptic number.

It is an amenable number.

21653153 is a deficient number, since it is larger than the sum of its proper divisors (1).

21653153 is an equidigital number, since it uses as much as digits as its factorization.

21653153 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2700, while the sum is 26.

The square root of 21653153 is about 4653.2948541867. The cubic root of 21653153 is about 278.7235821251.

Adding to 21653153 its reverse (35135612), we get a palindrome (56788765).

It can be divided in two parts, 2 and 1653153, that multiplied together give a triangular number (3306306 = T₂₅₇₁).

The spelling of 21653153 in words is "twenty-one million, six hundred fifty-three thousand, one hundred fifty-three".