21220930 has 32 divisors (see below), whose sum is σ = 41399424. Its totient is φ = 7800576.

The previous prime is 21220921. The next prime is 21220937. The reversal of 21220930 is 3902212.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21220898 and 21220907.

It is not an unprimeable number, because it can be changed into a prime (21220937) 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, 5859 + ... + 8761.

It is an arithmetic number, because the mean of its divisors is an integer number (1293732).

Almost surely, 2^21220930 is an apocalyptic number.

21220930 is a deficient number, since it is larger than the sum of its proper divisors (20178494).

21220930 is a wasteful number, since it uses less digits than its factorization.

21220930 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2970.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 21220930 is about 4606.6180653490. The cubic root of 21220930 is about 276.8565509909.

The spelling of 21220930 in words is "twenty-one million, two hundred twenty thousand, nine hundred thirty".