21620120 has 32 divisors (see below), whose sum is σ = 49835520. Its totient is φ = 8436480.

The previous prime is 21620117. The next prime is 21620129. The reversal of 21620120 is 2102612.

It is a junction number, because it is equal to n+sod(n) for n = 21620095 and 21620104.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21620129) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4952 + ... + 8231.

It is an arithmetic number, because the mean of its divisors is an integer number (1557360).

Almost surely, 2^21620120 is an apocalyptic number.

21620120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21620120 is an abundant number, since it is smaller than the sum of its proper divisors (28215400).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21620120 is a wasteful number, since it uses less digits than its factorization.

21620120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13235 (or 13231 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 21620120 is about 4649.7440789790. The cubic root of 21620120 is about 278.5817742628.

Adding to 21620120 its reverse (2102612), we get a palindrome (23722732).

The spelling of 21620120 in words is "twenty-one million, six hundred twenty thousand, one hundred twenty".