21153017 has 2 divisors, whose sum is σ = 21153018. Its totient is φ = 21153016.

The previous prime is 21152983. The next prime is 21153019. The reversal of 21153017 is 71035112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13623481 + 7529536 = 3691^2 + 2744^2 .

It is a cyclic number.

It is not a de Polignac number, because 21153017 - 2¹² = 21148921 is a prime.

Together with 21153019, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21153017.

It is not a weakly prime, because it can be changed into another prime (21153019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10576508 + 10576509.

It is an arithmetic number, because the mean of its divisors is an integer number (10576509).

Almost surely, 2^21153017 is an apocalyptic number.

It is an amenable number.

21153017 is a deficient number, since it is larger than the sum of its proper divisors (1).

21153017 is an equidigital number, since it uses as much as digits as its factorization.

21153017 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 210, while the sum is 20.

The square root of 21153017 is about 4599.2409156294. The cubic root of 21153017 is about 276.5608955209.

Adding to 21153017 its reverse (71035112), we get a palindrome (92188129).

The spelling of 21153017 in words is "twenty-one million, one hundred fifty-three thousand, seventeen".