21310120 has 64 divisors (see below), whose sum is σ = 52254720. Its totient is φ = 7774464.

The previous prime is 21310117. The next prime is 21310139. The reversal of 21310120 is 2101312.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 21310097 and 21310106.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55449 + ... + 55831.

It is an arithmetic number, because the mean of its divisors is an integer number (816480).

Almost surely, 2^21310120 is an apocalyptic number.

21310120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21310120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26127360).

21310120 is an abundant number, since it is smaller than the sum of its proper divisors (30944600).

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

21310120 is a wasteful number, since it uses less digits than its factorization.

21310120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 514 (or 510 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 21310120 is about 4616.2885525062. The cubic root of 21310120 is about 277.2438780666.

Adding to 21310120 its reverse (2101312), we get a palindrome (23411432).

The spelling of 21310120 in words is "twenty-one million, three hundred ten thousand, one hundred twenty".