16561042 has 4 divisors (see below), whose sum is σ = 24841566. Its totient is φ = 8280520.

The previous prime is 16561033. The next prime is 16561049. The reversal of 16561042 is 24016561.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 16329681 + 231361 = 4041^2 + 481^2 .

It is a super-2 number, since 2×16561042² = 548536224251528, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 16560998 and 16561016.

It is not an unprimeable number, because it can be changed into a prime (16561049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4140259 + ... + 4140262.

Almost surely, 2^16561042 is an apocalyptic number.

16561042 is a deficient number, since it is larger than the sum of its proper divisors (8280524).

16561042 is an equidigital number, since it uses as much as digits as its factorization.

16561042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8280523.

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

The square root of 16561042 is about 4069.5260166265. The cubic root of 16561042 is about 254.8957256603.

The spelling of 16561042 in words is "sixteen million, five hundred sixty-one thousand, forty-two".