64687919 has 2 divisors, whose sum is σ = 64687920. Its totient is φ = 64687918.

The previous prime is 64687901. The next prime is 64687927. The reversal of 64687919 is 91978646.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 64687919 - 2¹² = 64683823 is a prime.

It is a super-2 number, since 2×64687919² = 8369053729101122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64687949) by changing a digit.

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

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32343959 + 32343960.

It is an arithmetic number, because the mean of its divisors is an integer number (32343960).

Almost surely, 2^64687919 is an apocalyptic number.

64687919 is a deficient number, since it is larger than the sum of its proper divisors (1).

64687919 is an equidigital number, since it uses as much as digits as its factorization.

64687919 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 653184, while the sum is 50.

The square root of 64687919 is about 8042.8800189982. The cubic root of 64687919 is about 401.4280601267.

The spelling of 64687919 in words is "sixty-four million, six hundred eighty-seven thousand, nine hundred nineteen".