21220102 has 4 divisors (see below), whose sum is σ = 31830156. Its totient is φ = 10610050.

The previous prime is 21220019. The next prime is 21220103. The reversal of 21220102 is 20102212.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220103) 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 as a sum of consecutive naturals, namely, 5305024 + ... + 5305027.

It is an arithmetic number, because the mean of its divisors is an integer number (7957539).

Almost surely, 2^21220102 is an apocalyptic number.

21220102 is a deficient number, since it is larger than the sum of its proper divisors (10610054).

21220102 is a wasteful number, since it uses less digits than its factorization.

21220102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10610053.

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 21220102 is about 4606.5281937702. The cubic root of 21220102 is about 276.8529501402.

Adding to 21220102 its reverse (20102212), we get a palindrome (41322314).

It can be divided in two parts, 212 and 20102, that multiplied together give a palindrome (4261624).

The spelling of 21220102 in words is "twenty-one million, two hundred twenty thousand, one hundred two".