649969 has 2 divisors, whose sum is σ = 649970. Its totient is φ = 649968.

The previous prime is 649937. The next prime is 649981. The reversal of 649969 is 969946.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 435600 + 214369 = 660^2 + 463^2 .

It is a cyclic number.

It is not a de Polignac number, because 649969 - 2⁵ = 649937 is a prime.

It is a super-2 number, since 2×649969² = 844919401922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (649069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324984 + 324985.

It is an arithmetic number, because the mean of its divisors is an integer number (324985).

2⁶⁴⁹⁹⁶⁹ is an apocalyptic number.

It is an amenable number.

649969 is a deficient number, since it is larger than the sum of its proper divisors (1).

649969 is an equidigital number, since it uses as much as digits as its factorization.

649969 is an evil number, because the sum of its binary digits is even.

The product of its digits is 104976, while the sum is 43.

The square root of 649969 is about 806.2065492168. The cubic root of 649969 is about 86.6225334141.

It can be divided in two parts, 649 and 969, that multiplied together give a triangular number (628881 = T₁₁₂₁).

The spelling of 649969 in words is "six hundred forty-nine thousand, nine hundred sixty-nine".