16561240 has 16 divisors (see below), whose sum is σ = 37262880. Its totient is φ = 6624480.

The previous prime is 16561211. The next prime is 16561243. The reversal of 16561240 is 4216561.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16561243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 206976 + ... + 207055.

It is an arithmetic number, because the mean of its divisors is an integer number (2328930).

Almost surely, 2^16561240 is an apocalyptic number.

16561240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

16561240 is an abundant number, since it is smaller than the sum of its proper divisors (20701640).

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

16561240 is a wasteful number, since it uses less digits than its factorization.

16561240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 414042 (or 414038 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 16561240 is about 4069.5503437112. The cubic root of 16561240 is about 254.8967414811.

The spelling of 16561240 in words is "sixteen million, five hundred sixty-one thousand, two hundred forty".