16553987 has 4 divisors (see below), whose sum is σ = 16582776. Its totient is φ = 16525200.

The previous prime is 16553981. The next prime is 16553989. The reversal of 16553987 is 78935561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 78935561 = 3049 ⋅25889.

It is a cyclic number.

It is not a de Polignac number, because 16553987 - 2¹⁴ = 16537603 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16553981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13514 + ... + 14687.

It is an arithmetic number, because the mean of its divisors is an integer number (4145694).

Almost surely, 2^16553987 is an apocalyptic number.

16553987 is a deficient number, since it is larger than the sum of its proper divisors (28789).

16553987 is an equidigital number, since it uses as much as digits as its factorization.

16553987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28788.

The product of its digits is 226800, while the sum is 44.

The square root of 16553987 is about 4068.6591157284. The cubic root of 16553987 is about 254.8595253463.

The spelling of 16553987 in words is "sixteen million, five hundred fifty-three thousand, nine hundred eighty-seven".