64977919 has 2 divisors, whose sum is σ = 64977920. Its totient is φ = 64977918.

The previous prime is 64977917. The next prime is 64977931. The reversal of 64977919 is 91977946.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 64977919 - 2¹ = 64977917 is a prime.

It is a super-2 number, since 2×64977919² = 8444259915141122, which contains 22 as substring.

Together with 64977917, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64977917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32488959 + 32488960.

It is an arithmetic number, because the mean of its divisors is an integer number (32488960).

Almost surely, 2^64977919 is an apocalyptic number.

64977919 is a deficient number, since it is larger than the sum of its proper divisors (1).

64977919 is an equidigital number, since it uses as much as digits as its factorization.

64977919 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 857304, while the sum is 52.

The square root of 64977919 is about 8060.8882264922. Note that the first 3 decimals coincide. The cubic root of 64977919 is about 402.0270416534.

The spelling of 64977919 in words is "sixty-four million, nine hundred seventy-seven thousand, nine hundred nineteen".