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BaseRepresentation
bin1101011111000…
…0111011100101
310221102121121222
43113300323211
5103434431011
65340150125
71254522662
oct327607345
9127377558
1056561381
1129a22448
1216b38345
13b944a96
147724a69
154e73ddb
hex35f0ee5

56561381 has 2 divisors, whose sum is σ = 56561382. Its totient is φ = 56561380.

The previous prime is 56561371. The next prime is 56561389. The reversal of 56561381 is 18316565.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38328481 + 18232900 = 6191^2 + 4270^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2k-56561381 is a prime.

It is a super-2 number, since 2×565613812 = 6398379641254322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56561389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28280690 + 28280691.

It is an arithmetic number, because the mean of its divisors is an integer number (28280691).

Almost surely, 256561381 is an apocalyptic number.

It is an amenable number.

56561381 is a deficient number, since it is larger than the sum of its proper divisors (1).

56561381 is an equidigital number, since it uses as much as digits as its factorization.

56561381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21600, while the sum is 35.

The square root of 56561381 is about 7520.7300842405. The cubic root of 56561381 is about 383.8604206430.

The spelling of 56561381 in words is "fifty-six million, five hundred sixty-one thousand, three hundred eighty-one".