21158271 has 12 divisors (see below), whose sum is σ = 30766320. Its totient is φ = 14011200.

The previous prime is 21158261. The next prime is 21158273. The reversal of 21158271 is 17285112.

21158271 is a `hidden beast` number, since 2 + 11 + 582 + 71 = 666.

It is not a de Polignac number, because 21158271 - 2⁵ = 21158239 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21158273) 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, 6426 + ... + 9143.

It is an arithmetic number, because the mean of its divisors is an integer number (2563860).

Almost surely, 2^21158271 is an apocalyptic number.

21158271 is a deficient number, since it is larger than the sum of its proper divisors (9608049).

21158271 is a wasteful number, since it uses less digits than its factorization.

21158271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15726 (or 15723 counting only the distinct ones).

The product of its digits is 1120, while the sum is 27.

The square root of 21158271 is about 4599.8120613782. The cubic root of 21158271 is about 276.5837910833.

The spelling of 21158271 in words is "twenty-one million, one hundred fifty-eight thousand, two hundred seventy-one".