43894021081 has 27 divisors (see below), whose sum is σ = 46198332831. Its totient is φ = 41704023504.

The previous prime is 43894021043. The next prime is 43894021111. The reversal of 43894021081 is 18012049834.

The square root of 43894021081 is 209509.

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

43894021081 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 31643073225 + 12250947856 = 177885^2 + 110684^2 .

It is not a de Polignac number, because 43894021081 - 2⁷ = 43894020953 is a prime.

It is a super-2 number, since 2×43894021081² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (43894021021) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 655134610 + ... + 655134676.

Almost surely, 2^43894021081 is an apocalyptic number.

43894021081 is the 209509-th square number.

43894021081 is the 104755-th centered octagonal number.

It is an amenable number.

43894021081 is a deficient number, since it is larger than the sum of its proper divisors (2304311750).

43894021081 is an frugal number, since it uses more digits than its factorization.

43894021081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 358 (or 179 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 40.

The spelling of 43894021081 in words is "forty-three billion, eight hundred ninety-four million, twenty-one thousand, eighty-one".