649920 has 56 divisors (see below), whose sum is σ = 2066544. Its totient is φ = 173056.

The previous prime is 649907. The next prime is 649921. The reversal of 649920 is 29946.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a nialpdrome in base 15.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 649920.

It is not an unprimeable number, because it can be changed into a prime (649921) by changing a digit.

649920 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 622 + ... + 1298.

2⁶⁴⁹⁹²⁰ is an apocalyptic number.

649920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 649920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1033272).

649920 is an abundant number, since it is smaller than the sum of its proper divisors (1416624).

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

649920 is a wasteful number, since it uses less digits than its factorization.

649920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 697 (or 687 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 30.

The square root of 649920 is about 806.1761594093. The cubic root of 649920 is about 86.6203565868.

The spelling of 649920 in words is "six hundred forty-nine thousand, nine hundred twenty".