16488378581 has 4 divisors (see below), whose sum is σ = 17356188000. Its totient is φ = 15620569164.

The previous prime is 16488378559. The next prime is 16488378589. The reversal of 16488378581 is 18587388461.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18587388461 = 179 ⋅103840159.

It is a cyclic number.

It is not a de Polignac number, because 16488378581 - 2¹⁴ = 16488362197 is a prime.

It is a super-2 number, since 2×16488378581² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16488378581.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16488378589) 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, 433904681 + ... + 433904718.

It is an arithmetic number, because the mean of its divisors is an integer number (4339047000).

Almost surely, 2^16488378581 is an apocalyptic number.

It is an amenable number.

16488378581 is a deficient number, since it is larger than the sum of its proper divisors (867809419).

16488378581 is an equidigital number, since it uses as much as digits as its factorization.

16488378581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 867809418.

The product of its digits is 10321920, while the sum is 59.

The spelling of 16488378581 in words is "sixteen billion, four hundred eighty-eight million, three hundred seventy-eight thousand, five hundred eighty-one".