649979 has 8 divisors (see below), whose sum is σ = 728688. Its totient is φ = 574560.

The previous prime is 649969. The next prime is 649981. The reversal of 649979 is 979946.

649979 = T₂₃₂ + T₂₃₃ + ... + T₂₅₃.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-649979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (649969) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 392 + ... + 1205.

It is an arithmetic number, because the mean of its divisors is an integer number (91086).

2⁶⁴⁹⁹⁷⁹ is an apocalyptic number.

649979 is a deficient number, since it is larger than the sum of its proper divisors (78709).

649979 is a wasteful number, since it uses less digits than its factorization.

649979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1645.

The product of its digits is 122472, while the sum is 44.

The square root of 649979 is about 806.2127510775. The cubic root of 649979 is about 86.6229776512.

The spelling of 649979 in words is "six hundred forty-nine thousand, nine hundred seventy-nine".