21361208 has 32 divisors (see below), whose sum is σ = 44357760. Its totient is φ = 9562080.

The previous prime is 21361183. The next prime is 21361217. The reversal of 21361208 is 80216312.

It is a congruent number.

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, 4085 + ... + 7707.

It is an arithmetic number, because the mean of its divisors is an integer number (1386180).

Almost surely, 2^21361208 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21361208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22178880).

21361208 is an abundant number, since it is smaller than the sum of its proper divisors (22996552).

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

21361208 is a wasteful number, since it uses less digits than its factorization.

21361208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3707 (or 3703 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 21361208 is about 4621.8186896502. The cubic root of 21361208 is about 277.4652522571.

The spelling of 21361208 in words is "twenty-one million, three hundred sixty-one thousand, two hundred eight".