21543410179 has 2 divisors, whose sum is σ = 21543410180. Its totient is φ = 21543410178.

The previous prime is 21543410149. The next prime is 21543410219. The reversal of 21543410179 is 97101434512.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21543410179 - 2⁷ = 21543410051 is a prime.

It is not a weakly prime, because it can be changed into another prime (21543410149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10771705089 + 10771705090.

It is an arithmetic number, because the mean of its divisors is an integer number (10771705090).

Almost surely, 2^21543410179 is an apocalyptic number.

21543410179 is a deficient number, since it is larger than the sum of its proper divisors (1).

21543410179 is an equidigital number, since it uses as much as digits as its factorization.

21543410179 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30240, while the sum is 37.

The spelling of 21543410179 in words is "twenty-one billion, five hundred forty-three million, four hundred ten thousand, one hundred seventy-nine".