21838047 has 64 divisors (see below), whose sum is σ = 39481344. Its totient is φ = 10391040.

The previous prime is 21838027. The next prime is 21838057. The reversal of 21838047 is 74083812.

It is not a de Polignac number, because 21838047 - 2⁶ = 21837983 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 21837999 and 21838017.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21838027) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 263068 + ... + 263150.

It is an arithmetic number, because the mean of its divisors is an integer number (616896).

Almost surely, 2^21838047 is an apocalyptic number.

21838047 is a deficient number, since it is larger than the sum of its proper divisors (17643297).

21838047 is a wasteful number, since it uses less digits than its factorization.

21838047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188.

The product of its (nonzero) digits is 10752, while the sum is 33.

The square root of 21838047 is about 4673.1196218372. The cubic root of 21838047 is about 279.5146651889.

The spelling of 21838047 in words is "twenty-one million, eight hundred thirty-eight thousand, forty-seven".