21383387237 has 4 divisors (see below), whose sum is σ = 21495342336. Its totient is φ = 21271432140.

The previous prime is 21383387231. The next prime is 21383387239. The reversal of 21383387237 is 73278338312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21383387237 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21383387191 and 21383387200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21383387231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55977263 + ... + 55977644.

It is an arithmetic number, because the mean of its divisors is an integer number (5373835584).

Almost surely, 2^21383387237 is an apocalyptic number.

It is an amenable number.

21383387237 is a deficient number, since it is larger than the sum of its proper divisors (111955099).

21383387237 is a wasteful number, since it uses less digits than its factorization.

21383387237 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111955098.

The product of its digits is 1016064, while the sum is 47.

The spelling of 21383387237 in words is "twenty-one billion, three hundred eighty-three million, three hundred eighty-seven thousand, two hundred thirty-seven".