16561499 has 8 divisors (see below), whose sum is σ = 17085600. Its totient is φ = 16043200.

The previous prime is 16561469. The next prime is 16561507. The reversal of 16561499 is 99416561.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 16561499 - 2⁸ = 16561243 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16561469) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4754 + ... + 7464.

It is an arithmetic number, because the mean of its divisors is an integer number (2135700).

Almost surely, 2^16561499 is an apocalyptic number.

16561499 is a deficient number, since it is larger than the sum of its proper divisors (524101).

16561499 is a wasteful number, since it uses less digits than its factorization.

16561499 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2901.

The product of its digits is 58320, while the sum is 41.

The square root of 16561499 is about 4069.5821652843. The cubic root of 16561499 is about 254.8980702446.

The spelling of 16561499 in words is "sixteen million, five hundred sixty-one thousand, four hundred ninety-nine".