21423420129247 has 2 divisors, whose sum is σ = 21423420129248. Its totient is φ = 21423420129246.

The previous prime is 21423420129211. The next prime is 21423420129253. The reversal of 21423420129247 is 74292102432412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21423420129247 - 2³⁹ = 20873664315359 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21423420129847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10711710064623 + 10711710064624.

It is an arithmetic number, because the mean of its divisors is an integer number (10711710064624).

Almost surely, 2^{21423420129247} is an apocalyptic number.

21423420129247 is a deficient number, since it is larger than the sum of its proper divisors (1).

21423420129247 is an equidigital number, since it uses as much as digits as its factorization.

21423420129247 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 387072, while the sum is 43.

The spelling of 21423420129247 in words is "twenty-one trillion, four hundred twenty-three billion, four hundred twenty million, one hundred twenty-nine thousand, two hundred forty-seven".