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81977 = 73239
BaseRepresentation
bin10100000000111001
311011110012
4110000321
510110402
61431305
7461000
oct240071
9134405
1081977
1156655
123b535
132b40c
1421c37
1519452
hex14039

81977 has 8 divisors (see below), whose sum is σ = 96000. Its totient is φ = 69972.

The previous prime is 81973. The next prime is 82003. The reversal of 81977 is 77918.

Added to its reverse (77918) it gives a triangular number (159895 = T565).

It is not a de Polignac number, because 81977 - 22 = 81973 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81971) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 224 + ... + 462.

It is an arithmetic number, because the mean of its divisors is an integer number (12000).

281977 is an apocalyptic number.

It is an amenable number.

81977 is a deficient number, since it is larger than the sum of its proper divisors (14023).

81977 is an equidigital number, since it uses as much as digits as its factorization.

81977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 260 (or 246 counting only the distinct ones).

The product of its digits is 3528, while the sum is 32.

The square root of 81977 is about 286.3162587070. The cubic root of 81977 is about 43.4407525643.

Adding to 81977 its reverse (77918), we get a triangular number (159895 = T565).

The spelling of 81977 in words is "eighty-one thousand, nine hundred seventy-seven".

Divisors: 1 7 49 239 343 1673 11711 81977