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21892 = 2213421
BaseRepresentation
bin101010110000100
31010000211
411112010
51200032
6245204
7120553
oct52604
933024
1021892
11154a2
1210804
139c70
147d9a
156747
hex5584

21892 has 12 divisors (see below), whose sum is σ = 41356. Its totient is φ = 10080.

The previous prime is 21881. The next prime is 21893. The reversal of 21892 is 29812.

It can be written as a sum of positive squares in 2 ways, for example, as 1156 + 20736 = 34^2 + 144^2 .

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21893) by changing a digit.

21892 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 159 + ... + 262.

221892 is an apocalyptic number.

It is an amenable number.

21892 is a deficient number, since it is larger than the sum of its proper divisors (19464).

21892 is a wasteful number, since it uses less digits than its factorization.

21892 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 438 (or 436 counting only the distinct ones).

The product of its digits is 288, while the sum is 22.

The square root of 21892 is about 147.9594539055. The cubic root of 21892 is about 27.9744665188.

The spelling of 21892 in words is "twenty-one thousand, eight hundred ninety-two".

Divisors: 1 2 4 13 26 52 421 842 1684 5473 10946 21892