21630424 has 16 divisors (see below), whose sum is σ = 40737600. Its totient is φ = 10767072.

The previous prime is 21630421. The next prime is 21630439. The reversal of 21630424 is 42403612.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21630395 and 21630404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21630421) 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, 4072 + ... + 7735.

It is an arithmetic number, because the mean of its divisors is an integer number (2546100).

Almost surely, 2^21630424 is an apocalyptic number.

It is an amenable number.

21630424 is a deficient number, since it is larger than the sum of its proper divisors (19107176).

21630424 is a wasteful number, since it uses less digits than its factorization.

21630424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12042 (or 12038 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 21630424 is about 4650.8519649630. The cubic root of 21630424 is about 278.6260239509.

The spelling of 21630424 in words is "twenty-one million, six hundred thirty thousand, four hundred twenty-four".