21608359 has 2 divisors, whose sum is σ = 21608360. Its totient is φ = 21608358.

The previous prime is 21608347. The next prime is 21608369. The reversal of 21608359 is 95380612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21608359 - 2¹³ = 21600167 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21608369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10804179 + 10804180.

It is an arithmetic number, because the mean of its divisors is an integer number (10804180).

Almost surely, 2^21608359 is an apocalyptic number.

21608359 is a deficient number, since it is larger than the sum of its proper divisors (1).

21608359 is an equidigital number, since it uses as much as digits as its factorization.

21608359 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 21608359 is about 4648.4792136784. The cubic root of 21608359 is about 278.5312504216.

The spelling of 21608359 in words is "twenty-one million, six hundred eight thousand, three hundred fifty-nine".