21630417 has 16 divisors (see below), whose sum is σ = 30861120. Its totient is φ = 13435200.

The previous prime is 21630391. The next prime is 21630421. The reversal of 21630417 is 71403612.

It is not a de Polignac number, because 21630417 - 2⁶ = 21630353 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21630457) 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 15 ways as a sum of consecutive naturals, for example, 367 + ... + 6587.

It is an arithmetic number, because the mean of its divisors is an integer number (1928820).

Almost surely, 2^21630417 is an apocalyptic number.

It is an amenable number.

21630417 is a deficient number, since it is larger than the sum of its proper divisors (9230703).

21630417 is a wasteful number, since it uses less digits than its factorization.

21630417 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6304.

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 21630417 is about 4650.8512124126. The cubic root of 21630417 is about 278.6259938947.

The spelling of 21630417 in words is "twenty-one million, six hundred thirty thousand, four hundred seventeen".