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19621 = 72803
BaseRepresentation
bin100110010100101
3222220201
410302211
51111441
6230501
7111130
oct46245
928821
1019621
1113818
12b431
138c14
147217
155c31
hex4ca5

19621 has 4 divisors (see below), whose sum is σ = 22432. Its totient is φ = 16812.

The previous prime is 19609. The next prime is 19661. The reversal of 19621 is 12691.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 19621 - 211 = 17573 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1395 + ... + 1408.

It is an arithmetic number, because the mean of its divisors is an integer number (5608).

219621 is an apocalyptic number.

It is an amenable number.

19621 is a deficient number, since it is larger than the sum of its proper divisors (2811).

19621 is an equidigital number, since it uses as much as digits as its factorization.

19621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2810.

The product of its digits is 108, while the sum is 19.

The square root of 19621 is about 140.0749799215. The cubic root of 19621 is about 26.9716208447.

The spelling of 19621 in words is "nineteen thousand, six hundred twenty-one".

Divisors: 1 7 2803 19621