43091861 has 8 divisors (see below), whose sum is σ = 44269848. Its totient is φ = 41920000.

The previous prime is 43091837. The next prime is 43091863. The reversal of 43091861 is 16819034.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 14938225 + 28153636 = 3865^2 + 5306^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 43091861 - 2²² = 38897557 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43091863) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15131 + ... + 17751.

It is an arithmetic number, because the mean of its divisors is an integer number (5533731).

Almost surely, 2^43091861 is an apocalyptic number.

43091861 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

It is an amenable number.

43091861 is a deficient number, since it is larger than the sum of its proper divisors (1177987).

43091861 is a wasteful number, since it uses less digits than its factorization.

43091861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3063.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 43091861 is about 6564.4391230325. The cubic root of 43091861 is about 350.5891058437.

The spelling of 43091861 in words is "forty-three million, ninety-one thousand, eight hundred sixty-one".