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21051493 is a prime number
BaseRepresentation
bin101000001001…
…1100001100101
31110121112012221
41100103201211
520342121433
62031112341
7343635421
oct120234145
943545187
1021051493
1110979331
1270726b1
134490c08
142b1db81
151cac72d
hex1413865

21051493 has 2 divisors, whose sum is σ = 21051494. Its totient is φ = 21051492.

The previous prime is 21051479. The next prime is 21051523. The reversal of 21051493 is 39415012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12159169 + 8892324 = 3487^2 + 2982^2 .

It is a cyclic number.

It is not a de Polignac number, because 21051493 - 25 = 21051461 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21051403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10525746 + 10525747.

It is an arithmetic number, because the mean of its divisors is an integer number (10525747).

Almost surely, 221051493 is an apocalyptic number.

It is an amenable number.

21051493 is a deficient number, since it is larger than the sum of its proper divisors (1).

21051493 is an equidigital number, since it uses as much as digits as its factorization.

21051493 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 21051493 is about 4588.1906019694. The cubic root of 21051493 is about 276.1177340248.

The spelling of 21051493 in words is "twenty-one million, fifty-one thousand, four hundred ninety-three".