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21838745 = 54367749
BaseRepresentation
bin101001101001…
…1101110011001
31112002112010102
41103103232121
521042314440
62100025145
7353424545
oct123235631
945075112
1021838745
1111366855
1273921b5
1346a8346
142c86a25
151db5b15
hex14d3b99

21838745 has 4 divisors (see below), whose sum is σ = 26206500. Its totient is φ = 17470992.

The previous prime is 21838723. The next prime is 21838763. The reversal of 21838745 is 54783812.

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

It can be written as a sum of positive squares in 2 ways, for example, as 6574096 + 15264649 = 2564^2 + 3907^2 .

It is a cyclic number.

It is not a de Polignac number, because 21838745 - 218 = 21576601 is a prime.

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

It is a junction number, because it is equal to n+sod(n) for n = 21838699 and 21838708.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2183870 + ... + 2183879.

It is an arithmetic number, because the mean of its divisors is an integer number (6551625).

Almost surely, 221838745 is an apocalyptic number.

It is an amenable number.

21838745 is a deficient number, since it is larger than the sum of its proper divisors (4367755).

21838745 is an equidigital number, since it uses as much as digits as its factorization.

21838745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4367754.

The product of its digits is 53760, while the sum is 38.

The square root of 21838745 is about 4673.1943036856. The cubic root of 21838745 is about 279.5176431590.

The spelling of 21838745 in words is "twenty-one million, eight hundred thirty-eight thousand, seven hundred forty-five".

Divisors: 1 5 4367749 21838745