649879 has 2 divisors, whose sum is σ = 649880. Its totient is φ = 649878.

The previous prime is 649877. The next prime is 649897. The reversal of 649879 is 978946.

Together with next prime (649897) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 649879 - 2¹ = 649877 is a prime.

Together with 649877, it forms a pair of twin primes.

It is a d-powerful number, because it can be written as 6² + 4² + 8 + 9³ + 7⁶ + 9⁶ .

It is a nialpdrome in base 15.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (649871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324939 + 324940.

It is an arithmetic number, because the mean of its divisors is an integer number (324940).

2⁶⁴⁹⁸⁷⁹ is an apocalyptic number.

649879 is a deficient number, since it is larger than the sum of its proper divisors (1).

649879 is an equidigital number, since it uses as much as digits as its factorization.

649879 is an evil number, because the sum of its binary digits is even.

The product of its digits is 108864, while the sum is 43.

The square root of 649879 is about 806.1507303228. The cubic root of 649879 is about 86.6185350758.

The spelling of 649879 in words is "six hundred forty-nine thousand, eight hundred seventy-nine".