21311600 has 30 divisors (see below), whose sum is σ = 51202080. Its totient is φ = 8524480.

The previous prime is 21311599. The next prime is 21311603. The reversal of 21311600 is 611312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21311603) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 26240 + ... + 27039.

It is an arithmetic number, because the mean of its divisors is an integer number (1706736).

Almost surely, 2^21311600 is an apocalyptic number.

21311600 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21311600 is an abundant number, since it is smaller than the sum of its proper divisors (29890480).

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

21311600 is a wasteful number, since it uses less digits than its factorization.

21311600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53297 (or 53286 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 14.

The square root of 21311600 is about 4616.4488516608. The cubic root of 21311600 is about 277.2502961665.

Adding to 21311600 its reverse (611312), we get a palindrome (21922912).

The spelling of 21311600 in words is "twenty-one million, three hundred eleven thousand, six hundred".