21153153 has 32 divisors (see below), whose sum is σ = 33529600. Its totient is φ = 11854080.

The previous prime is 21153133. The next prime is 21153161. The reversal of 21153153 is 35135112.

It is not a de Polignac number, because 21153153 - 2¹² = 21149057 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21153113) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 62601 + ... + 62937.

It is an arithmetic number, because the mean of its divisors is an integer number (1047800).

Almost surely, 2^21153153 is an apocalyptic number.

It is an amenable number.

21153153 is a deficient number, since it is larger than the sum of its proper divisors (12376447).

21153153 is an equidigital number, since it uses as much as digits as its factorization.

21153153 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 422 (or 408 counting only the distinct ones).

The product of its digits is 450, while the sum is 21.

The square root of 21153153 is about 4599.2557006542. The cubic root of 21153153 is about 276.5614882213.

Adding to 21153153 its reverse (35135112), we get a palindrome (56288265).

The spelling of 21153153 in words is "twenty-one million, one hundred fifty-three thousand, one hundred fifty-three".