16563139 has 4 divisors (see below), whose sum is σ = 16967160. Its totient is φ = 16159120.

The previous prime is 16563133. The next prime is 16563143. The reversal of 16563139 is 93136561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93136561 = 7 ⋅13305223.

It is a cyclic number.

It is not a de Polignac number, because 16563139 - 2⁹ = 16562627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16563133) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 201949 + ... + 202030.

It is an arithmetic number, because the mean of its divisors is an integer number (4241790).

Almost surely, 2^16563139 is an apocalyptic number.

16563139 is a deficient number, since it is larger than the sum of its proper divisors (404021).

16563139 is an equidigital number, since it uses as much as digits as its factorization.

16563139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404020.

The product of its digits is 14580, while the sum is 34.

The square root of 16563139 is about 4069.7836551837. The cubic root of 16563139 is about 254.9064837148.

The spelling of 16563139 in words is "sixteen million, five hundred sixty-three thousand, one hundred thirty-nine".