64878889 has 2 divisors, whose sum is σ = 64878890. Its totient is φ = 64878888.

The previous prime is 64878841. The next prime is 64878899. The reversal of 64878889 is 98887846.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39275289 + 25603600 = 6267^2 + 5060^2 .

It is a cyclic number.

It is not a de Polignac number, because 64878889 - 2¹⁵ = 64846121 is a prime.

It is not a weakly prime, because it can be changed into another prime (64878899) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32439444 + 32439445.

It is an arithmetic number, because the mean of its divisors is an integer number (32439445).

Almost surely, 2^64878889 is an apocalyptic number.

It is an amenable number.

64878889 is a deficient number, since it is larger than the sum of its proper divisors (1).

64878889 is an equidigital number, since it uses as much as digits as its factorization.

64878889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6193152, while the sum is 58.

The square root of 64878889 is about 8054.7432609612. The cubic root of 64878889 is about 401.8227005413.

It can be divided in two parts, 6487 and 8889, that added together give a square (15376 = 124²).

The spelling of 64878889 in words is "sixty-four million, eight hundred seventy-eight thousand, eight hundred eighty-nine".