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18916013 = 87721569
BaseRepresentation
bin100100000101…
…0001010101101
31022121000220002
41020022022231
514320303023
61513234045
7316532504
oct110121255
938530802
1018916013
11a74a976
126402925
133bc3c0c
14272583b
1519d9b28
hex120a2ad

18916013 has 4 divisors (see below), whose sum is σ = 18938460. Its totient is φ = 18893568.

The previous prime is 18915989. The next prime is 18916031. The reversal of 18916013 is 31061981.

It is a happy number.

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 7171684 + 11744329 = 2678^2 + 3427^2 .

It is a cyclic number.

It is not a de Polignac number, because 18916013 - 212 = 18911917 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18916063) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9908 + ... + 11661.

It is an arithmetic number, because the mean of its divisors is an integer number (4734615).

Almost surely, 218916013 is an apocalyptic number.

It is an amenable number.

18916013 is a deficient number, since it is larger than the sum of its proper divisors (22447).

18916013 is an equidigital number, since it uses as much as digits as its factorization.

18916013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22446.

The product of its (nonzero) digits is 1296, while the sum is 29.

The square root of 18916013 is about 4349.2543039008. The cubic root of 18916013 is about 266.4464068364.

Adding to 18916013 its reverse (31061981), we get a palindrome (49977994).

The spelling of 18916013 in words is "eighteen million, nine hundred sixteen thousand, thirteen".

Divisors: 1 877 21569 18916013