649990 has 32 divisors (see below), whose sum is σ = 1347840. Its totient is φ = 223200.

The previous prime is 649981. The next prime is 649991. The reversal of 649990 is 99946.

649990 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (649991) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1935 + ... + 2245.

It is an arithmetic number, because the mean of its divisors is an integer number (42120).

2⁶⁴⁹⁹⁹⁰ is an apocalyptic number.

649990 is an abundant number, since it is smaller than the sum of its proper divisors (697850).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

649990 is a wasteful number, since it uses less digits than its factorization.

649990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 348.

The product of its (nonzero) digits is 17496, while the sum is 37.

The square root of 649990 is about 806.2195730693. The cubic root of 649990 is about 86.6234663066.

The spelling of 649990 in words is "six hundred forty-nine thousand, nine hundred ninety".