64543561 has 2 divisors, whose sum is σ = 64543562. Its totient is φ = 64543560.

The previous prime is 64543541. The next prime is 64543573. The reversal of 64543561 is 16534546.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58614336 + 5929225 = 7656^2 + 2435^2 .

It is a cyclic number.

It is not a de Polignac number, because 64543561 - 2⁵ = 64543529 is a prime.

It is not a weakly prime, because it can be changed into another prime (64543511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32271780 + 32271781.

It is an arithmetic number, because the mean of its divisors is an integer number (32271781).

Almost surely, 2^64543561 is an apocalyptic number.

It is an amenable number.

64543561 is a deficient number, since it is larger than the sum of its proper divisors (1).

64543561 is an equidigital number, since it uses as much as digits as its factorization.

64543561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 43200, while the sum is 34.

The square root of 64543561 is about 8033.9007337656. The cubic root of 64543561 is about 401.1292278612.

The spelling of 64543561 in words is "sixty-four million, five hundred forty-three thousand, five hundred sixty-one".