21361238 has 4 divisors (see below), whose sum is σ = 32041860. Its totient is φ = 10680618.

The previous prime is 21361237. The next prime is 21361259. The reversal of 21361238 is 83216312.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21361237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5340308 + ... + 5340311.

It is an arithmetic number, because the mean of its divisors is an integer number (8010465).

Almost surely, 2^21361238 is an apocalyptic number.

21361238 is a deficient number, since it is larger than the sum of its proper divisors (10680622).

21361238 is a wasteful number, since it uses less digits than its factorization.

21361238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10680621.

The product of its digits is 1728, while the sum is 26.

The square root of 21361238 is about 4621.8219351247. The cubic root of 21361238 is about 277.4653821492.

The spelling of 21361238 in words is "twenty-one million, three hundred sixty-one thousand, two hundred thirty-eight".