21311120 has 40 divisors (see below), whose sum is σ = 49740864. Its totient is φ = 8491392.

The previous prime is 21311117. The next prime is 21311123. The reversal of 21311120 is 2111312.

It is an interprime number because it is at equal distance from previous prime (21311117) and next prime (21311123).

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

It is not an unprimeable number, because it can be changed into a prime (21311123) 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, 38687 + ... + 39233.

Almost surely, 2^21311120 is an apocalyptic number.

21311120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21311120 is an abundant number, since it is smaller than the sum of its proper divisors (28429744).

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

21311120 is a wasteful number, since it uses less digits than its factorization.

21311120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1047 (or 1041 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 21311120 is about 4616.3968633557. The cubic root of 21311120 is about 277.2482146532.

Adding to 21311120 its reverse (2111312), we get a palindrome (23422432).

The spelling of 21311120 in words is "twenty-one million, three hundred eleven thousand, one hundred twenty".