64919251 has 2 divisors, whose sum is σ = 64919252. Its totient is φ = 64919250.

The previous prime is 64919249. The next prime is 64919269. The reversal of 64919251 is 15291946.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 64919251 - 2¹ = 64919249 is a prime.

Together with 64919249, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 64919251.

It is not a weakly prime, because it can be changed into another prime (64919221) 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, 32459625 + 32459626.

It is an arithmetic number, because the mean of its divisors is an integer number (32459626).

Almost surely, 2^64919251 is an apocalyptic number.

64919251 is a deficient number, since it is larger than the sum of its proper divisors (1).

64919251 is an equidigital number, since it uses as much as digits as its factorization.

64919251 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 19440, while the sum is 37.

The square root of 64919251 is about 8057.2483516397. The cubic root of 64919251 is about 401.9060096425.

It can be divided in two parts, 649 and 19251, that added together give a triangular number (19900 = T₁₉₉).

The spelling of 64919251 in words is "sixty-four million, nine hundred nineteen thousand, two hundred fifty-one".