654440 has 16 divisors (see below), whose sum is σ = 1472580. Its totient is φ = 261760.

The previous prime is 654439. The next prime is 654491. The reversal of 654440 is 44456.

Added to its reverse (44456) it gives a square (698896 = 836²).

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 643204 + 11236 = 802^2 + 106^2 .

It is a nialpdrome in base 10.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8141 + ... + 8220.

2⁶⁵⁴⁴⁴⁰ is an apocalyptic number.

It is an amenable number.

654440 is an abundant number, since it is smaller than the sum of its proper divisors (818140).

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

654440 is a wasteful number, since it uses less digits than its factorization.

654440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16372 (or 16368 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 654440 is about 808.9746596773. The cubic root of 654440 is about 86.8206991204.

Adding to 654440 its reverse (44456), we get a palindrome (698896).

The spelling of 654440 in words is "six hundred fifty-four thousand, four hundred forty".