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81095121 = 3310912753
BaseRepresentation
bin1001101010101…
…10100111010001
312122121001121000
410311112213101
5131230020441
612014052213
72003203632
oct465264721
9178531530
1081095121
1141859a68
12231aa069
1313a549a3
14aaad889
1571bd2b6
hex4d569d1

81095121 has 16 divisors (see below), whose sum is σ = 120294720. Its totient is φ = 53994240.

The previous prime is 81095099. The next prime is 81095129. The reversal of 81095121 is 12159018.

It is not a de Polignac number, because 81095121 - 26 = 81095057 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (81095129) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28081 + ... + 30833.

It is an arithmetic number, because the mean of its divisors is an integer number (7518420).

Almost surely, 281095121 is an apocalyptic number.

It is an amenable number.

81095121 is a deficient number, since it is larger than the sum of its proper divisors (39199599).

81095121 is a wasteful number, since it uses less digits than its factorization.

81095121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3853 (or 3847 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 27.

The square root of 81095121 is about 9005.2829494692. The cubic root of 81095121 is about 432.8441730118.

The spelling of 81095121 in words is "eighty-one million, ninety-five thousand, one hundred twenty-one".

Divisors: 1 3 9 27 1091 2753 3273 8259 9819 24777 29457 74331 3003523 9010569 27031707 81095121