21836425 has 12 divisors (see below), whose sum is σ = 29160460. Its totient is φ = 16125120.

The previous prime is 21836413. The next prime is 21836429. The reversal of 21836425 is 52463812.

It can be written as a sum of positive squares in 6 ways, for example, as 36864 + 21799561 = 192^2 + 4669^2 .

It is a de Polignac number, because none of the positive numbers 2^k-21836425 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21836429) 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 11 ways as a sum of consecutive naturals, for example, 33270 + ... + 33919.

Almost surely, 2^21836425 is an apocalyptic number.

21836425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21836425 is a deficient number, since it is larger than the sum of its proper divisors (7324035).

21836425 is a wasteful number, since it uses less digits than its factorization.

21836425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67212 (or 67207 counting only the distinct ones).

The product of its digits is 11520, while the sum is 31.

The square root of 21836425 is about 4672.9460728752. The cubic root of 21836425 is about 279.5077447896.

The spelling of 21836425 in words is "twenty-one million, eight hundred thirty-six thousand, four hundred twenty-five".