21838743 has 6 divisors (see below), whose sum is σ = 31544864. Its totient is φ = 14559156.

The previous prime is 21838723. The next prime is 21838763. The reversal of 21838743 is 34783812.

It is an interprime number because it is at equal distance from previous prime (21838723) and next prime (21838763).

It is not a de Polignac number, because 21838743 - 2⁶ = 21838679 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21838698 and 21838707.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21838723) 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, 1213255 + ... + 1213272.

Almost surely, 2^21838743 is an apocalyptic number.

21838743 is a deficient number, since it is larger than the sum of its proper divisors (9706121).

21838743 is a wasteful number, since it uses less digits than its factorization.

21838743 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2426533 (or 2426530 counting only the distinct ones).

The product of its digits is 32256, while the sum is 36.

The square root of 21838743 is about 4673.1940896992. The cubic root of 21838743 is about 279.5176346263.

The spelling of 21838743 in words is "twenty-one million, eight hundred thirty-eight thousand, seven hundred forty-three".