21836930 has 16 divisors (see below), whose sum is σ = 39425400. Its totient is φ = 8708352.

The previous prime is 21836921. The next prime is 21836939. The reversal of 21836930 is 3963812.

It is a Cunningham number, because it is equal to 4673²+1.

It is an interprime number because it is at equal distance from previous prime (21836921) and next prime (21836939).

It can be written as a sum of positive squares in 4 ways, for example, as 21836929 + 1 = 4673^2 + 1^2 .

It is not an unprimeable number, because it can be changed into a prime (21836939) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 362 + ... + 6618.

Almost surely, 2^21836930 is an apocalyptic number.

21836930 is a deficient number, since it is larger than the sum of its proper divisors (17588470).

21836930 is a wasteful number, since it uses less digits than its factorization.

21836930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6613.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 21836930 is about 4673.0001069976. Note that the first 3 decimals coincide. The cubic root of 21836930 is about 279.5098994513.

The spelling of 21836930 in words is "twenty-one million, eight hundred thirty-six thousand, nine hundred thirty".