649769 has 2 divisors, whose sum is σ = 649770. Its totient is φ = 649768.

The previous prime is 649751. The next prime is 649771. The reversal of 649769 is 967946.

649769 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 582169 + 67600 = 763^2 + 260^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-649769 is a prime.

It is a super-2 number, since 2×649769² = 844399506722, which contains 22 as substring.

Together with 649771, 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 (649709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324884 + 324885.

It is an arithmetic number, because the mean of its divisors is an integer number (324885).

2⁶⁴⁹⁷⁶⁹ is an apocalyptic number.

It is an amenable number.

649769 is a deficient number, since it is larger than the sum of its proper divisors (1).

649769 is an equidigital number, since it uses as much as digits as its factorization.

649769 is an evil number, because the sum of its binary digits is even.

The product of its digits is 81648, while the sum is 41.

The square root of 649769 is about 806.0825019810. The cubic root of 649769 is about 86.6136477165.

The spelling of 649769 in words is "six hundred forty-nine thousand, seven hundred sixty-nine".