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81923001 = 3531274057
BaseRepresentation
bin1001110001000…
…00101110111001
312201011010020020
410320200232321
5131433014001
612043521053
72013222366
oct470405671
9181133206
1081923001
1142274a66
1223529189
1313c84764
14ac4746d
1572d3736
hex4e20bb9

81923001 has 16 divisors (see below), whose sum is σ = 112195584. Its totient is φ = 53149824.

The previous prime is 81922991. The next prime is 81923053. The reversal of 81923001 is 10032918.

It is not a de Polignac number, because 81923001 - 25 = 81922969 is a prime.

It is a super-2 number, since 2×819230012 = 13422756185692002, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81921001) 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 in 15 ways as a sum of consecutive naturals, for example, 18165 + ... + 22221.

It is an arithmetic number, because the mean of its divisors is an integer number (7012224).

Almost surely, 281923001 is an apocalyptic number.

It is an amenable number.

81923001 is a deficient number, since it is larger than the sum of its proper divisors (30272583).

81923001 is a wasteful number, since it uses less digits than its factorization.

81923001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4240.

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 81923001 is about 9051.1325810641. The cubic root of 81923001 is about 434.3121219545.

Adding to 81923001 its reverse (10032918), we get a palindrome (91955919).

The spelling of 81923001 in words is "eighty-one million, nine hundred twenty-three thousand, one".

Divisors: 1 3 53 127 159 381 4057 6731 12171 20193 215021 515239 645063 1545717 27307667 81923001