21142343 has 2 divisors, whose sum is σ = 21142344. Its totient is φ = 21142342.

The previous prime is 21142291. The next prime is 21142349. The reversal of 21142343 is 34324112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21142343 - 2⁸ = 21142087 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21142349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10571171 + 10571172.

It is an arithmetic number, because the mean of its divisors is an integer number (10571172).

Almost surely, 2^21142343 is an apocalyptic number.

21142343 is a deficient number, since it is larger than the sum of its proper divisors (1).

21142343 is an equidigital number, since it uses as much as digits as its factorization.

21142343 is an evil number, because the sum of its binary digits is even.

The product of its digits is 576, while the sum is 20.

The square root of 21142343 is about 4598.0803603243. The cubic root of 21142343 is about 276.5143693339.

Adding to 21142343 its reverse (34324112), we get a palindrome (55466455).

The spelling of 21142343 in words is "twenty-one million, one hundred forty-two thousand, three hundred forty-three".