21854233 has 2 divisors, whose sum is σ = 21854234. Its totient is φ = 21854232.

The previous prime is 21854227. The next prime is 21854251. The reversal of 21854233 is 33245812.

It is the 1909-th star number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21790224 + 64009 = 4668^2 + 253^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21854233 is a prime.

It is not a weakly prime, because it can be changed into another prime (21854263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10927116 + 10927117.

It is an arithmetic number, because the mean of its divisors is an integer number (10927117).

Almost surely, 2^21854233 is an apocalyptic number.

It is an amenable number.

21854233 is a deficient number, since it is larger than the sum of its proper divisors (1).

21854233 is an equidigital number, since it uses as much as digits as its factorization.

21854233 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5760, while the sum is 28.

The square root of 21854233 is about 4674.8511206241. The cubic root of 21854233 is about 279.5837053534.

The spelling of 21854233 in words is "twenty-one million, eight hundred fifty-four thousand, two hundred thirty-three".