16555440 has 80 divisors (see below), whose sum is σ = 55996416. Its totient is φ = 4012800.

The previous prime is 16555439. The next prime is 16555481. The reversal of 16555440 is 4455561.

It is a tau number, because it is divible by the number of its divisors (80).

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

It is a junction number, because it is equal to n+sod(n) for n = 16555398 and 16555407.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 496 + ... + 5775.

Almost surely, 2^16555440 is an apocalyptic number.

16555440 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 16555440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27998208).

16555440 is an abundant number, since it is smaller than the sum of its proper divisors (39440976).

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

16555440 is a wasteful number, since it uses less digits than its factorization.

16555440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6298 (or 6292 counting only the distinct ones).

The product of its (nonzero) digits is 12000, while the sum is 30.

The square root of 16555440 is about 4068.8376718665. The cubic root of 16555440 is about 254.8669817586.

The spelling of 16555440 in words is "sixteen million, five hundred fifty-five thousand, four hundred forty".