43159394515561 has 3 divisors (see below), whose sum is σ = 43159401085143. Its totient is φ = 43159387945980.

The previous prime is 43159394515481. The next prime is 43159394515619. The reversal of 43159394515561 is 16551549395134.

The square root of 43159394515561 is 6569581.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 41414617705561 + 1744776810000 = 6435419^2 + 1320900^2 .

It is not a de Polignac number, because 43159394515561 - 2²⁹ = 43158857644649 is a prime.

It is a super-2 number, since 2×43159394515561² (a number of 28 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 43159394515561.

It is not an unprimeable number, because it can be changed into a prime (43159394515661) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 3284791 + ... + 9854371.

It is an arithmetic number, because the mean of its divisors is an integer number (14386467028381).

Almost surely, 2^{43159394515561} is an apocalyptic number.

43159394515561 is the 6569581-st square number.

43159394515561 is the 3284791-st centered octagonal number.

It is an amenable number.

43159394515561 is a deficient number, since it is larger than the sum of its proper divisors (6569582).

43159394515561 is an frugal number, since it uses more digits than its factorization.

43159394515561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13139162 (or 6569581 counting only the distinct ones).

The product of its digits is 43740000, while the sum is 61.

The spelling of 43159394515561 in words is "forty-three trillion, one hundred fifty-nine billion, three hundred ninety-four million, five hundred fifteen thousand, five hundred sixty-one".