21089953 has 2 divisors, whose sum is σ = 21089954. Its totient is φ = 21089952.

The previous prime is 21089947. The next prime is 21089969. The reversal of 21089953 is 35998012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14653584 + 6436369 = 3828^2 + 2537^2 .

It is a cyclic number.

It is not a de Polignac number, because 21089953 - 2⁵ = 21089921 is a prime.

It is a super-2 number, since 2×21089953² = 889572235084418, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21089903) 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, 10544976 + 10544977.

It is an arithmetic number, because the mean of its divisors is an integer number (10544977).

Almost surely, 2^21089953 is an apocalyptic number.

It is an amenable number.

21089953 is a deficient number, since it is larger than the sum of its proper divisors (1).

21089953 is an equidigital number, since it uses as much as digits as its factorization.

21089953 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 19440, while the sum is 37.

The square root of 21089953 is about 4592.3798841124. The cubic root of 21089953 is about 276.2857827156.

The spelling of 21089953 in words is "twenty-one million, eighty-nine thousand, nine hundred fifty-three".