21670630 has 8 divisors (see below), whose sum is σ = 39007152. Its totient is φ = 8668248.

The previous prime is 21670609. The next prime is 21670633. The reversal of 21670630 is 3607612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21670595 and 21670604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21670633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1083522 + ... + 1083541.

It is an arithmetic number, because the mean of its divisors is an integer number (4875894).

Almost surely, 2^21670630 is an apocalyptic number.

21670630 is a deficient number, since it is larger than the sum of its proper divisors (17336522).

21670630 is a wasteful number, since it uses less digits than its factorization.

21670630 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2167070.

The product of its (nonzero) digits is 1512, while the sum is 25.

The square root of 21670630 is about 4655.1723920817. The cubic root of 21670630 is about 278.7985510691.

The spelling of 21670630 in words is "twenty-one million, six hundred seventy thousand, six hundred thirty".