21023120 has 40 divisors (see below), whose sum is σ = 51455040. Its totient is φ = 7966080.

The previous prime is 21023117. The next prime is 21023137. The reversal of 21023120 is 2132012.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5396 + ... + 8435.

It is an arithmetic number, because the mean of its divisors is an integer number (1286376).

Almost surely, 2^21023120 is an apocalyptic number.

21023120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21023120 is an abundant number, since it is smaller than the sum of its proper divisors (30431920).

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

21023120 is a wasteful number, since it uses less digits than its factorization.

21023120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13863 (or 13857 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 21023120 is about 4585.0975998336. The cubic root of 21023120 is about 275.9936286424.

Adding to 21023120 its reverse (2132012), we get a palindrome (23155132).

The spelling of 21023120 in words is "twenty-one million, twenty-three thousand, one hundred twenty".