21954271 has 4 divisors (see below), whose sum is σ = 22065912. Its totient is φ = 21842632.

The previous prime is 21954263. The next prime is 21954281. The reversal of 21954271 is 17245912.

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 21954271 - 2³ = 21954263 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21954211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55525 + ... + 55918.

It is an arithmetic number, because the mean of its divisors is an integer number (5516478).

Almost surely, 2^21954271 is an apocalyptic number.

21954271 is a deficient number, since it is larger than the sum of its proper divisors (111641).

21954271 is a wasteful number, since it uses less digits than its factorization.

21954271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111640.

The product of its digits is 5040, while the sum is 31.

The square root of 21954271 is about 4685.5384962670. The cubic root of 21954271 is about 280.0096552793.

The spelling of 21954271 in words is "twenty-one million, nine hundred fifty-four thousand, two hundred seventy-one".