21854887 has 2 divisors, whose sum is σ = 21854888. Its totient is φ = 21854886.

The previous prime is 21854869. The next prime is 21854891. The reversal of 21854887 is 78845812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21854887 - 2²³ = 13466279 is a prime.

It is a plaindrome in base 11.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21854837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10927443 + 10927444.

It is an arithmetic number, because the mean of its divisors is an integer number (10927444).

Almost surely, 2^21854887 is an apocalyptic number.

21854887 is a deficient number, since it is larger than the sum of its proper divisors (1).

21854887 is an equidigital number, since it uses as much as digits as its factorization.

21854887 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 143360, while the sum is 43.

The square root of 21854887 is about 4674.9210688524. The cubic root of 21854887 is about 279.5864942245.

The spelling of 21854887 in words is "twenty-one million, eight hundred fifty-four thousand, eight hundred eighty-seven".