64749569 has 2 divisors, whose sum is σ = 64749570. Its totient is φ = 64749568.

The previous prime is 64749563. The next prime is 64749571. The reversal of 64749569 is 96594746.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 45495025 + 19254544 = 6745^2 + 4388^2 .

It is a cyclic number.

It is not a de Polignac number, because 64749569 - 2⁸ = 64749313 is a prime.

It is a super-2 number, since 2×64749569² = 8385013371371522, which contains 22 as substring.

Together with 64749571, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (64749563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32374784 + 32374785.

It is an arithmetic number, because the mean of its divisors is an integer number (32374785).

It is a Proth number, since it is equal to 247 ⋅ 2¹⁸ + 1 and 247 < 2¹⁸.

Almost surely, 2^64749569 is an apocalyptic number.

It is an amenable number.

64749569 is a deficient number, since it is larger than the sum of its proper divisors (1).

64749569 is an equidigital number, since it uses as much as digits as its factorization.

64749569 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1632960, while the sum is 50.

The square root of 64749569 is about 8046.7116886341. The cubic root of 64749569 is about 401.5555449415. Note that the first 4 decimals are identical.

The spelling of 64749569 in words is "sixty-four million, seven hundred forty-nine thousand, five hundred sixty-nine".