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BaseRepresentation
bin11110100001001000010101
3120001102222002
4132201020111
54022000041
6443245045
7124666451
oct36411025
916042862
108000021
114574597
122819785
131871453
1410c3661
15a8059b
hex7a1215

8000021 has 8 divisors (see below), whose sum is σ = 8543040. Its totient is φ = 7473312.

The previous prime is 8000017. The next prime is 8000023. The reversal of 8000021 is 1200008.

Adding to 8000021 its reverse (1200008), we get a palindrome (9200029).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 8000021 - 22 = 8000017 is a prime.

It is a Duffinian number.

8000021 is a modest number, since divided by 21 gives 8 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 7999966 and 8000011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8000023) 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, 3056 + ... + 5033.

It is an arithmetic number, because the mean of its divisors is an integer number (1067880).

Almost surely, 28000021 is an apocalyptic number.

It is an amenable number.

8000021 is a deficient number, since it is larger than the sum of its proper divisors (543019).

8000021 is a wasteful number, since it uses less digits than its factorization.

8000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8155.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 8000021 is about 2828.4308370544. The cubic root of 8000021 is about 200.0001749998. Note that the first 3 decimals are identical.

The spelling of 8000021 in words is "eight million, twenty-one", and thus it is an aban number and an uban number.

Divisors: 1 23 43 989 8089 186047 347827 8000021