21271753 has 4 divisors (see below), whose sum is σ = 21284608. Its totient is φ = 21258900.

The previous prime is 21271751. The next prime is 21271787. The reversal of 21271753 is 35717212.

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 21271753 - 2¹ = 21271751 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21271751) 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, 3501 + ... + 7402.

It is an arithmetic number, because the mean of its divisors is an integer number (5321152).

Almost surely, 2^21271753 is an apocalyptic number.

It is an amenable number.

21271753 is a deficient number, since it is larger than the sum of its proper divisors (12855).

21271753 is a wasteful number, since it uses less digits than its factorization.

21271753 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12854.

The product of its digits is 2940, while the sum is 28.

The square root of 21271753 is about 4612.1310692564. The cubic root of 21271753 is about 277.0773936931.

Adding to 21271753 its reverse (35717212), we get a palindrome (56988965).

The spelling of 21271753 in words is "twenty-one million, two hundred seventy-one thousand, seven hundred fifty-three".