21144953 has 2 divisors, whose sum is σ = 21144954. Its totient is φ = 21144952.

The previous prime is 21144947. The next prime is 21144989. The reversal of 21144953 is 35944112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21132409 + 12544 = 4597^2 + 112^2 .

It is a cyclic number.

It is not a de Polignac number, because 21144953 - 2¹² = 21140857 is a prime.

It is a super-3 number, since 3×21144953³ (a number of 23 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (21144553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10572476 + 10572477.

It is an arithmetic number, because the mean of its divisors is an integer number (10572477).

Almost surely, 2^21144953 is an apocalyptic number.

It is an amenable number.

21144953 is a deficient number, since it is larger than the sum of its proper divisors (1).

21144953 is an equidigital number, since it uses as much as digits as its factorization.

21144953 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4320, while the sum is 29.

The square root of 21144953 is about 4598.3641656572. The cubic root of 21144953 is about 276.5257473350.

The spelling of 21144953 in words is "twenty-one million, one hundred forty-four thousand, nine hundred fifty-three".