649751 has 2 divisors, whose sum is σ = 649752. Its totient is φ = 649750.

The previous prime is 649739. The next prime is 649769. The reversal of 649751 is 157946.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-649751 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (649771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324875 + 324876.

It is an arithmetic number, because the mean of its divisors is an integer number (324876).

2⁶⁴⁹⁷⁵¹ is an apocalyptic number.

649751 is a deficient number, since it is larger than the sum of its proper divisors (1).

649751 is an equidigital number, since it uses as much as digits as its factorization.

649751 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7560, while the sum is 32.

The square root of 649751 is about 806.0713367935. The cubic root of 649751 is about 86.6128479143.

The spelling of 649751 in words is "six hundred forty-nine thousand, seven hundred fifty-one".