21253153 has 12 divisors (see below), whose sum is σ = 22672548. Its totient is φ = 19918080.

The previous prime is 21253121. The next prime is 21253181. The reversal of 21253153 is 35135212.

It can be written as a sum of positive squares in 2 ways, for example, as 2486929 + 18766224 = 1577^2 + 4332^2 .

It is not a de Polignac number, because 21253153 - 2⁵ = 21253121 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21253103) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 40533 + ... + 41053.

It is an arithmetic number, because the mean of its divisors is an integer number (1889379).

Almost surely, 2^21253153 is an apocalyptic number.

It is an amenable number.

21253153 is a deficient number, since it is larger than the sum of its proper divisors (1419395).

21253153 is a wasteful number, since it uses less digits than its factorization.

21253153 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 672 (or 653 counting only the distinct ones).

The product of its digits is 900, while the sum is 22.

The square root of 21253153 is about 4610.1142068283. The cubic root of 21253153 is about 276.9966114092.

Adding to 21253153 its reverse (35135212), we get a palindrome (56388365).

The spelling of 21253153 in words is "twenty-one million, two hundred fifty-three thousand, one hundred fifty-three".