21071153 has 4 divisors (see below), whose sum is σ = 21086448. Its totient is φ = 21055860.

The previous prime is 21071137. The next prime is 21071179. The reversal of 21071153 is 35117012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21071153 - 2⁴ = 21071137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21071123) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5351 + ... + 8412.

It is an arithmetic number, because the mean of its divisors is an integer number (5271612).

Almost surely, 2^21071153 is an apocalyptic number.

It is an amenable number.

21071153 is a deficient number, since it is larger than the sum of its proper divisors (15295).

21071153 is a wasteful number, since it uses less digits than its factorization.

21071153 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15294.

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

The square root of 21071153 is about 4590.3325587587. The cubic root of 21071153 is about 276.2036627780.

Adding to 21071153 its reverse (35117012), we get a palindrome (56188165).

The spelling of 21071153 in words is "twenty-one million, seventy-one thousand, one hundred fifty-three".