21271151 has 4 divisors (see below), whose sum is σ = 23204904. Its totient is φ = 19337400.

The previous prime is 21271141. The next prime is 21271153. The reversal of 21271151 is 15117212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21271151 - 2²² = 17076847 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21271153) 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, 966860 + ... + 966881.

It is an arithmetic number, because the mean of its divisors is an integer number (5801226).

Almost surely, 2^21271151 is an apocalyptic number.

21271151 is a deficient number, since it is larger than the sum of its proper divisors (1933753).

21271151 is a wasteful number, since it uses less digits than its factorization.

21271151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1933752.

The product of its digits is 140, while the sum is 20.

The square root of 21271151 is about 4612.0658061220. The cubic root of 21271151 is about 277.0747798642.

Adding to 21271151 its reverse (15117212), we get a palindrome (36388363).

It can be divided in two parts, 21 and 271151, that added together give a palindrome (271172).

The spelling of 21271151 in words is "twenty-one million, two hundred seventy-one thousand, one hundred fifty-one".