649440 has 144 divisors (see below), whose sum is σ = 2476656. Its totient is φ = 153600.

The previous prime is 649427. The next prime is 649457. The reversal of 649440 is 44946.

It is a tau number, because it is divible by the number of its divisors (144).

It is a nialpdrome in base 15.

It is a congruent number.

It is an unprimeable number.

649440 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 23 ways as a sum of consecutive naturals, for example, 15820 + ... + 15860.

It is an arithmetic number, because the mean of its divisors is an integer number (17199).

2⁶⁴⁹⁴⁴⁰ is an apocalyptic number.

649440 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 649440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1238328).

649440 is an abundant number, since it is smaller than the sum of its proper divisors (1827216).

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

649440 is a wasteful number, since it uses less digits than its factorization.

649440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73 (or 62 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 649440 is about 805.8784027383. The cubic root of 649440 is about 86.5990267764.

It can be divided in two parts, 649 and 440, that added together give a square (1089 = 33²).

The spelling of 649440 in words is "six hundred forty-nine thousand, four hundred forty".