21026271 has 16 divisors (see below), whose sum is σ = 32140800. Its totient is φ = 11977248.

The previous prime is 21026267. The next prime is 21026287. The reversal of 21026271 is 17262012.

It is not a de Polignac number, because 21026271 - 2² = 21026267 is a prime.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21026231) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6145 + ... + 8933.

It is an arithmetic number, because the mean of its divisors is an integer number (2008800).

Almost surely, 2^21026271 is an apocalyptic number.

21026271 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21026271 is a deficient number, since it is larger than the sum of its proper divisors (11114529).

21026271 is a wasteful number, since it uses less digits than its factorization.

21026271 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3158.

The product of its (nonzero) digits is 336, while the sum is 21.

The square root of 21026271 is about 4585.4412001464. The cubic root of 21026271 is about 276.0074168349.

Adding to 21026271 its reverse (17262012), we get a palindrome (38288283).

The spelling of 21026271 in words is "twenty-one million, twenty-six thousand, two hundred seventy-one".