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71961289 = 1724992
BaseRepresentation
bin1000100101000…
…00101011001001
312000102000022221
410102200223021
5121410230124
611050214041
71532442451
oct422405311
9160360287
1071961289
1137690644
1220124321
1311ba745a
1497b2d61
1564b6ce4
hex44a0ac9

71961289 has 9 divisors (see below), whose sum is σ = 76596807. Its totient is φ = 67592544.

The previous prime is 71961287. The next prime is 71961299. The reversal of 71961289 is 98216917.

The square root of 71961289 is 8483.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 56025225 + 15936064 = 7485^2 + 3992^2 .

It is not a de Polignac number, because 71961289 - 21 = 71961287 is a prime.

It is a super-2 number, since 2×719612892 = 10356854229083042, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71961287) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 143962 + ... + 144460.

Almost surely, 271961289 is an apocalyptic number.

71961289 is the 8483-rd square number.

71961289 is the 4242-nd centered octagonal number.

It is an amenable number.

71961289 is a deficient number, since it is larger than the sum of its proper divisors (4635518).

71961289 is an frugal number, since it uses more digits than its factorization.

71961289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1032 (or 516 counting only the distinct ones).

The product of its digits is 54432, while the sum is 43.

The cubic root of 71961289 is about 415.9421937213.

The spelling of 71961289 in words is "seventy-one million, nine hundred sixty-one thousand, two hundred eighty-nine".

Divisors: 1 17 289 499 8483 144211 249001 4233017 71961289