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2640891 = 311791013
BaseRepresentation
bin1010000100101111111011
311222011121210
422010233323
51134002031
6132334203
731306251
oct12045773
94864553
102640891
111544160
12a74363
13716076
144ca5d1
15372746
hex284bfb

2640891 has 16 divisors (see below), whose sum is σ = 3893760. Its totient is φ = 1578720.

The previous prime is 2640889. The next prime is 2640893. The reversal of 2640891 is 1980462.

2640891 = T54 + T55 + ... + T251.

It is an interprime number because it is at equal distance from previous prime (2640889) and next prime (2640893).

It is not a de Polignac number, because 2640891 - 21 = 2640889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2640893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2101 + ... + 3113.

It is an arithmetic number, because the mean of its divisors is an integer number (243360).

22640891 is an apocalyptic number.

2640891 is the 869-th nonagonal number.

2640891 is a deficient number, since it is larger than the sum of its proper divisors (1252869).

2640891 is a wasteful number, since it uses less digits than its factorization.

2640891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1106.

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 2640891 is about 1625.0818440928. The cubic root of 2640891 is about 138.2240113036.

The spelling of 2640891 in words is "two million, six hundred forty thousand, eight hundred ninety-one".

Divisors: 1 3 11 33 79 237 869 1013 2607 3039 11143 33429 80027 240081 880297 2640891