21450887 has 2 divisors, whose sum is σ = 21450888. Its totient is φ = 21450886.

The previous prime is 21450859. The next prime is 21450899. The reversal of 21450887 is 78805412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21450887 - 2⁸ = 21450631 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21450827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10725443 + 10725444.

It is an arithmetic number, because the mean of its divisors is an integer number (10725444).

Almost surely, 2^21450887 is an apocalyptic number.

21450887 is a deficient number, since it is larger than the sum of its proper divisors (1).

21450887 is an equidigital number, since it uses as much as digits as its factorization.

21450887 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17920, while the sum is 35.

The square root of 21450887 is about 4631.5102288562. The cubic root of 21450887 is about 277.8529966550.

The spelling of 21450887 in words is "twenty-one million, four hundred fifty thousand, eight hundred eighty-seven".