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BaseRepresentation
bin101001111110100
31002111000
411033310
51141432
6243300
7116442
oct51764
932430
1021492
1115169
1210530
139a23
147b92
15657c
hex53f4

21492 has 24 divisors (see below), whose sum is σ = 56000. Its totient is φ = 7128.

The previous prime is 21491. The next prime is 21493. The reversal of 21492 is 29412.

It is an interprime number because it is at equal distance from previous prime (21491) and next prime (21493).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nude number because it is divisible by every one of its digits.

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 (21491) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9 + ... + 207.

221492 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21492, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28000).

21492 is an abundant number, since it is smaller than the sum of its proper divisors (34508).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21492 is a wasteful number, since it uses less digits than its factorization.

21492 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212 (or 204 counting only the distinct ones).

The product of its digits is 144, while the sum is 18.

The square root of 21492 is about 146.6015006744. The cubic root of 21492 is about 27.8030395379.

The spelling of 21492 in words is "twenty-one thousand, four hundred ninety-two".