21854263 has 2 divisors, whose sum is σ = 21854264. Its totient is φ = 21854262.

The previous prime is 21854251. The next prime is 21854269. The reversal of 21854263 is 36245812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21854263 - 2⁹ = 21853751 is a prime.

It is a super-2 number, since 2×21854263² = 955217622546338, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21854269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10927131 + 10927132.

It is an arithmetic number, because the mean of its divisors is an integer number (10927132).

Almost surely, 2^21854263 is an apocalyptic number.

21854263 is a deficient number, since it is larger than the sum of its proper divisors (1).

21854263 is an equidigital number, since it uses as much as digits as its factorization.

21854263 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11520, while the sum is 31.

The square root of 21854263 is about 4674.8543292813. The cubic root of 21854263 is about 279.5838332844.

The spelling of 21854263 in words is "twenty-one million, eight hundred fifty-four thousand, two hundred sixty-three".