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21138775 = 527199607
BaseRepresentation
bin101000010100…
…0110101010111
31110202221221121
41100220311113
520402420100
62033024411
7344451040
oct120506527
943687847
1021138775
1110a28969
1270b5107
1344c1868
142b438c7
151cc851a
hex1428d57

21138775 has 24 divisors (see below), whose sum is σ = 30156800. Its totient is φ = 14398560.

The previous prime is 21138751. The next prime is 21138781. The reversal of 21138775 is 57783112.

21138775 = T106 + T107 + ... + T503.

It is not a de Polignac number, because 21138775 - 221 = 19041623 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21138775.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 34522 + ... + 35128.

Almost surely, 221138775 is an apocalyptic number.

21138775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21138775 is a deficient number, since it is larger than the sum of its proper divisors (9018025).

21138775 is a wasteful number, since it uses less digits than its factorization.

21138775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 823 (or 818 counting only the distinct ones).

The product of its digits is 11760, while the sum is 34.

The square root of 21138775 is about 4597.6923559542. The cubic root of 21138775 is about 276.4988135245.

The spelling of 21138775 in words is "twenty-one million, one hundred thirty-eight thousand, seven hundred seventy-five".

Divisors: 1 5 7 25 35 175 199 607 995 1393 3035 4249 4975 6965 15175 21245 34825 106225 120793 603965 845551 3019825 4227755 21138775