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81497 = 136269
BaseRepresentation
bin10011111001011001
311010210102
4103321121
510101442
61425145
7456413
oct237131
9133712
1081497
1156259
123b1b5
132b130
14219b3
1519232
hex13e59

81497 has 4 divisors (see below), whose sum is σ = 87780. Its totient is φ = 75216.

The previous prime is 81463. The next prime is 81509. The reversal of 81497 is 79418.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 79418 = 239709.

It can be written as a sum of positive squares in 2 ways, for example, as 18496 + 63001 = 136^2 + 251^2 .

It is a cyclic number.

It is not a de Polignac number, because 81497 - 210 = 80473 is a prime.

It is a super-2 number, since 2×814972 = 13283522018, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81457) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3122 + ... + 3147.

It is an arithmetic number, because the mean of its divisors is an integer number (21945).

281497 is an apocalyptic number.

It is an amenable number.

81497 is a deficient number, since it is larger than the sum of its proper divisors (6283).

81497 is a wasteful number, since it uses less digits than its factorization.

81497 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6282.

The product of its digits is 2016, while the sum is 29.

The square root of 81497 is about 285.4767941532. The cubic root of 81497 is about 43.3558003154.

The spelling of 81497 in words is "eighty-one thousand, four hundred ninety-seven".

Divisors: 1 13 6269 81497