21409624279 has 2 divisors, whose sum is σ = 21409624280. Its totient is φ = 21409624278.

The previous prime is 21409624273. The next prime is 21409624283. The reversal of 21409624279 is 97242690412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21409624279 - 2⁷ = 21409624151 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21409624273) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10704812139 + 10704812140.

It is an arithmetic number, because the mean of its divisors is an integer number (10704812140).

Almost surely, 2^21409624279 is an apocalyptic number.

21409624279 is a deficient number, since it is larger than the sum of its proper divisors (1).

21409624279 is an equidigital number, since it uses as much as digits as its factorization.

21409624279 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 435456, while the sum is 46.

The spelling of 21409624279 in words is "twenty-one billion, four hundred nine million, six hundred twenty-four thousand, two hundred seventy-nine".