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81925271 = 130162971
BaseRepresentation
bin1001110001000…
…01010010010111
312201011020100022
410320201102113
5131433102041
612043535355
72013232121
oct470412227
9181136308
1081925271
114227673a
122352a55b
1313c857bc
14ac48211
1572d424b
hex4e21497

81925271 has 4 divisors (see below), whose sum is σ = 81989544. Its totient is φ = 81861000.

The previous prime is 81925247. The next prime is 81925279. The reversal of 81925271 is 17252918.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17252918 = 28626459.

It is a cyclic number.

It is not a de Polignac number, because 81925271 - 214 = 81908887 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81925279) 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, 30185 + ... + 32786.

It is an arithmetic number, because the mean of its divisors is an integer number (20497386).

Almost surely, 281925271 is an apocalyptic number.

81925271 is a deficient number, since it is larger than the sum of its proper divisors (64273).

81925271 is a wasteful number, since it uses less digits than its factorization.

81925271 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64272.

The product of its digits is 10080, while the sum is 35.

The square root of 81925271 is about 9051.2579788668. The cubic root of 81925271 is about 434.3161333612.

The spelling of 81925271 in words is "eighty-one million, nine hundred twenty-five thousand, two hundred seventy-one".

Divisors: 1 1301 62971 81925271