21799963 has 4 divisors (see below), whose sum is σ = 22263840. Its totient is φ = 21336088.

The previous prime is 21799937. The next prime is 21799979. The reversal of 21799963 is 36999712.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21799963 - 2²¹ = 19702811 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21799363) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 231868 + ... + 231961.

It is an arithmetic number, because the mean of its divisors is an integer number (5565960).

Almost surely, 2^21799963 is an apocalyptic number.

21799963 is a deficient number, since it is larger than the sum of its proper divisors (463877).

21799963 is an equidigital number, since it uses as much as digits as its factorization.

21799963 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 463876.

The product of its digits is 183708, while the sum is 46.

The square root of 21799963 is about 4669.0430497052. The cubic root of 21799963 is about 279.3520860814.

The spelling of 21799963 in words is "twenty-one million, seven hundred ninety-nine thousand, nine hundred sixty-three".