21816703 has 2 divisors, whose sum is σ = 21816704. Its totient is φ = 21816702.

The previous prime is 21816701. The next prime is 21816721. The reversal of 21816703 is 30761812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21816703 - 2¹ = 21816701 is a prime.

Together with 21816701, it forms a pair of twin primes.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21816701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10908351 + 10908352.

It is an arithmetic number, because the mean of its divisors is an integer number (10908352).

Almost surely, 2^21816703 is an apocalyptic number.

21816703 is a deficient number, since it is larger than the sum of its proper divisors (1).

21816703 is an equidigital number, since it uses as much as digits as its factorization.

21816703 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 21816703 is about 4670.8353642577. The cubic root of 21816703 is about 279.4235717907.

The spelling of 21816703 in words is "twenty-one million, eight hundred sixteen thousand, seven hundred three".