43490781 has 6 divisors (see below), whose sum is σ = 62820030. Its totient is φ = 28993848.

The previous prime is 43490779. The next prime is 43490801. The reversal of 43490781 is 18709434.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 26101881 + 17388900 = 5109^2 + 4170^2 .

It is not a de Polignac number, because 43490781 - 2¹ = 43490779 is a prime.

It is a super-2 number, since 2×43490781² = 3782896063979922, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43490731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2416146 + ... + 2416163.

It is an arithmetic number, because the mean of its divisors is an integer number (10470005).

Almost surely, 2^43490781 is an apocalyptic number.

It is an amenable number.

43490781 is a deficient number, since it is larger than the sum of its proper divisors (19329249).

43490781 is a wasteful number, since it uses less digits than its factorization.

43490781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4832315 (or 4832312 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 43490781 is about 6594.7540515170. The cubic root of 43490781 is about 351.6676361940.

The spelling of 43490781 in words is "forty-three million, four hundred ninety thousand, seven hundred eighty-one".