21717383 has 2 divisors, whose sum is σ = 21717384. Its totient is φ = 21717382.

The previous prime is 21717373. The next prime is 21717407. The reversal of 21717383 is 38371712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21717383 - 2¹⁴ = 21700999 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 (21717373) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10858691 + 10858692.

It is an arithmetic number, because the mean of its divisors is an integer number (10858692).

Almost surely, 2^21717383 is an apocalyptic number.

21717383 is a deficient number, since it is larger than the sum of its proper divisors (1).

21717383 is an equidigital number, since it uses as much as digits as its factorization.

21717383 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7056, while the sum is 32.

The square root of 21717383 is about 4660.1913050861. The cubic root of 21717383 is about 278.9989037439.

The spelling of 21717383 in words is "twenty-one million, seven hundred seventeen thousand, three hundred eighty-three".