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7217101681 = 171121337861
BaseRepresentation
bin1101011100010110…
…00011101101110001
3200121222020202022021
412232023003231301
5104240034223211
63152051311441
7343563231526
oct65613035561
920558222267
107217101681
113073958349
121494bab581
138b029a38a
144c671114d
152c3900771
hex1ae2c3b71

7217101681 has 8 divisors (see below), whose sum is σ = 7642520424. Its totient is φ = 6791781120.

The previous prime is 7217101669. The next prime is 7217101687. The reversal of 7217101681 is 1861017127.

It can be written as a sum of positive squares in 4 ways, for example, as 2059707456 + 5157394225 = 45384^2 + 71815^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 7217101681 - 213 = 7217093489 is a prime.

It is a super-2 number, since 2×72171016812 (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7217101687) 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, 171691 + ... + 209551.

It is an arithmetic number, because the mean of its divisors is an integer number (955315053).

Almost surely, 27217101681 is an apocalyptic number.

It is an amenable number.

7217101681 is a deficient number, since it is larger than the sum of its proper divisors (425418743).

7217101681 is a wasteful number, since it uses less digits than its factorization.

7217101681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49091.

The product of its (nonzero) digits is 4704, while the sum is 34.

The square root of 7217101681 is about 84953.5265954275. The cubic root of 7217101681 is about 1932.5064021562.

The spelling of 7217101681 in words is "seven billion, two hundred seventeen million, one hundred one thousand, six hundred eighty-one".

Divisors: 1 17 11213 37861 190621 643637 424535393 7217101681