21620122 has 4 divisors (see below), whose sum is σ = 32430186. Its totient is φ = 10810060.

The previous prime is 21620117. The next prime is 21620129. The reversal of 21620122 is 22102612.

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

It can be written as a sum of positive squares in only one way, i.e., 21261321 + 358801 = 4611^2 + 599^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21620096 and 21620105.

It is not an unprimeable number, because it can be changed into a prime (21620129) 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 as a sum of consecutive naturals, namely, 5405029 + ... + 5405032.

Almost surely, 2^21620122 is an apocalyptic number.

21620122 is a deficient number, since it is larger than the sum of its proper divisors (10810064).

21620122 is a wasteful number, since it uses less digits than its factorization.

21620122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10810063.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 21620122 is about 4649.7442940446. The cubic root of 21620122 is about 278.5817828530.

Adding to 21620122 its reverse (22102612), we get a palindrome (43722734).

The spelling of 21620122 in words is "twenty-one million, six hundred twenty thousand, one hundred twenty-two".