16381563 has 16 divisors (see below), whose sum is σ = 23895552. Its totient is φ = 9900000.

The previous prime is 16381513. The next prime is 16381577. The reversal of 16381563 is 36518361.

It is not a de Polignac number, because 16381563 - 2⁸ = 16381307 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (16381513) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21438 + ... + 22188.

It is an arithmetic number, because the mean of its divisors is an integer number (1493472).

Almost surely, 2^16381563 is an apocalyptic number.

16381563 is a deficient number, since it is larger than the sum of its proper divisors (7513989).

16381563 is a wasteful number, since it uses less digits than its factorization.

16381563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1426.

The product of its digits is 12960, while the sum is 33.

The square root of 16381563 is about 4047.4143598105. The cubic root of 16381563 is about 253.9715749289.

It can be divided in two parts, 163815 and 63, that added together give a triangular number (163878 = T₅₇₂).

The spelling of 16381563 in words is "sixteen million, three hundred eighty-one thousand, five hundred sixty-three".