21954211 has 2 divisors, whose sum is σ = 21954212. Its totient is φ = 21954210.

The previous prime is 21954199. The next prime is 21954227. The reversal of 21954211 is 11245912.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21954211 - 2¹³ = 21946019 is a prime.

It is not a weakly prime, because it can be changed into another prime (21954241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10977105 + 10977106.

It is an arithmetic number, because the mean of its divisors is an integer number (10977106).

Almost surely, 2^21954211 is an apocalyptic number.

21954211 is a deficient number, since it is larger than the sum of its proper divisors (1).

21954211 is an equidigital number, since it uses as much as digits as its factorization.

21954211 is an evil number, because the sum of its binary digits is even.

The product of its digits is 720, while the sum is 25.

The square root of 21954211 is about 4685.5320935834. The cubic root of 21954211 is about 280.0094001946.

The spelling of 21954211 in words is "twenty-one million, nine hundred fifty-four thousand, two hundred eleven".