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131205391 is a prime number
BaseRepresentation
bin1111101001000…
…00100100001111
3100010212220221221
413310200210033
5232042033031
621004104211
73152141002
oct764404417
9303786857
10131205391
1168075609
1237b35067
132124b335
14135d5539
15b7baa11
hex7d2090f

131205391 has 2 divisors, whose sum is σ = 131205392. Its totient is φ = 131205390.

The previous prime is 131205359. The next prime is 131205419. The reversal of 131205391 is 193502131.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 131205391 - 25 = 131205359 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (131205301) 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 as a sum of consecutive naturals, namely, 65602695 + 65602696.

It is an arithmetic number, because the mean of its divisors is an integer number (65602696).

Almost surely, 2131205391 is an apocalyptic number.

131205391 is a deficient number, since it is larger than the sum of its proper divisors (1).

131205391 is an equidigital number, since it uses as much as digits as its factorization.

131205391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 810, while the sum is 25.

The square root of 131205391 is about 11454.4921755615. The cubic root of 131205391 is about 508.1405967404.

The spelling of 131205391 in words is "one hundred thirty-one million, two hundred five thousand, three hundred ninety-one".