21849803 has 2 divisors, whose sum is σ = 21849804. Its totient is φ = 21849802.

The previous prime is 21849799. The next prime is 21849809. The reversal of 21849803 is 30894812.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21849803 - 2² = 21849799 is a prime.

It is a super-2 number, since 2×21849803² = 954827782277618, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21849809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10924901 + 10924902.

It is an arithmetic number, because the mean of its divisors is an integer number (10924902).

Almost surely, 2^21849803 is an apocalyptic number.

21849803 is a deficient number, since it is larger than the sum of its proper divisors (1).

21849803 is an equidigital number, since it uses as much as digits as its factorization.

21849803 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 21849803 is about 4674.3772847300. The cubic root of 21849803 is about 279.5648129110.

The spelling of 21849803 in words is "twenty-one million, eight hundred forty-nine thousand, eight hundred three".