21443087 has 2 divisors, whose sum is σ = 21443088. Its totient is φ = 21443086.

The previous prime is 21443083. The next prime is 21443099. The reversal of 21443087 is 78034412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21443087 - 2² = 21443083 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21443083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10721543 + 10721544.

It is an arithmetic number, because the mean of its divisors is an integer number (10721544).

Almost surely, 2^21443087 is an apocalyptic number.

21443087 is a deficient number, since it is larger than the sum of its proper divisors (1).

21443087 is an equidigital number, since it uses as much as digits as its factorization.

21443087 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5376, while the sum is 29.

The square root of 21443087 is about 4630.6680943466. The cubic root of 21443087 is about 277.8193148137.

Adding to 21443087 its reverse (78034412), we get a palindrome (99477499).

The spelling of 21443087 in words is "twenty-one million, four hundred forty-three thousand, eighty-seven".