16431535137889 has 9 divisors (see below), whose sum is σ = 16537501734867. Its totient is φ = 16326243319464.

The previous prime is 16431535137877. The next prime is 16431535137923. The reversal of 16431535137889 is 98873153513461.

The square root of 16431535137889 is 4053583.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 4816334998225 + 11615200139664 = 2194615^2 + 3408108^2 .

It is not a de Polignac number, because 16431535137889 - 2¹⁵ = 16431535105121 is a prime.

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 16431535137889.

It is not an unprimeable number, because it can be changed into a prime (16431536137889) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 636399622 + ... + 636425440.

It is an arithmetic number, because the mean of its divisors is an integer number (1837500192763).

Almost surely, 2^{16431535137889} is an apocalyptic number.

16431535137889 is the 4053583-rd square number.

16431535137889 is the 2026792-nd centered octagonal number.

It is an amenable number.

16431535137889 is a deficient number, since it is larger than the sum of its proper divisors (105966596978).

16431535137889 is an frugal number, since it uses more digits than its factorization.

16431535137889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51952 (or 25976 counting only the distinct ones).

The product of its digits is 65318400, while the sum is 64.

The spelling of 16431535137889 in words is "sixteen trillion, four hundred thirty-one billion, five hundred thirty-five million, one hundred thirty-seven thousand, eight hundred eighty-nine".