1649440 has 72 divisors (see below), whose sum is σ = 4288788. Its totient is φ = 599040.

The previous prime is 1649429. The next prime is 1649443. The reversal of 1649440 is 449461.

1649440 = T₁₉₂ + T₁₉₃ + ... + T₂₅₆.

It can be written as a sum of positive squares in 6 ways, for example, as 784 + 1648656 = 28^2 + 1284^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1649399 and 1649408.

It is not an unprimeable number, because it can be changed into a prime (1649443) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 27010 + ... + 27070.

2^1649440 is an apocalyptic number.

1649440 is a gapful number since it is divisible by the number (10) 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 1649440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2144394).

1649440 is an abundant number, since it is smaller than the sum of its proper divisors (2639348).

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

1649440 is a wasteful number, since it uses less digits than its factorization.

1649440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102 (or 81 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 1649440 is about 1284.3052596638. The cubic root of 1649440 is about 118.1532051943.

It can be divided in two parts, 164 and 9440, that added together give a square (9604 = 98²).

The spelling of 1649440 in words is "one million, six hundred forty-nine thousand, four hundred forty".