21899803 has 2 divisors, whose sum is σ = 21899804. Its totient is φ = 21899802.

The previous prime is 21899783. The next prime is 21899831. The reversal of 21899803 is 30899812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21899803 - 2¹⁷ = 21768731 is a prime.

It is not a weakly prime, because it can be changed into another prime (21899303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10949901 + 10949902.

It is an arithmetic number, because the mean of its divisors is an integer number (10949902).

Almost surely, 2^21899803 is an apocalyptic number.

21899803 is a deficient number, since it is larger than the sum of its proper divisors (1).

21899803 is an equidigital number, since it uses as much as digits as its factorization.

21899803 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 21899803 is about 4679.7225345099. The cubic root of 21899803 is about 279.7778978499. Note that the first 3 decimals are identical.

Subtracting 21899803 from its reverse (30899812), we obtain a palindrome (9000009).

The spelling of 21899803 in words is "twenty-one million, eight hundred ninety-nine thousand, eight hundred three".