43649991 has 24 divisors (see below), whose sum is σ = 78609024. Its totient is φ = 22674960.

The previous prime is 43649989. The next prime is 43650007. The reversal of 43649991 is 19994634.

43649991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 43649991 - 2¹ = 43649989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43649941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 30801 + ... + 32186.

It is an arithmetic number, because the mean of its divisors is an integer number (3275376).

Almost surely, 2^43649991 is an apocalyptic number.

43649991 is a deficient number, since it is larger than the sum of its proper divisors (34959033).

43649991 is a wasteful number, since it uses less digits than its factorization.

43649991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63011 (or 63008 counting only the distinct ones).

The product of its digits is 209952, while the sum is 45.

The square root of 43649991 is about 6606.8139825486. The cubic root of 43649991 is about 352.0962390735.

The spelling of 43649991 in words is "forty-three million, six hundred forty-nine thousand, nine hundred ninety-one".