43542991 has 4 divisors (see below), whose sum is σ = 43762000. Its totient is φ = 43323984.

The previous prime is 43542973. The next prime is 43542997. The reversal of 43542991 is 19924534.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 43542991 - 2⁹ = 43542479 is a prime.

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 43542991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43542997) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 109206 + ... + 109603.

It is an arithmetic number, because the mean of its divisors is an integer number (10940500).

Almost surely, 2^43542991 is an apocalyptic number.

43542991 is a deficient number, since it is larger than the sum of its proper divisors (219009).

43542991 is a wasteful number, since it uses less digits than its factorization.

43542991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 219008.

The product of its digits is 38880, while the sum is 37.

The square root of 43542991 is about 6598.7113135824. The cubic root of 43542991 is about 351.8083037452.

The spelling of 43542991 in words is "forty-three million, five hundred forty-two thousand, nine hundred ninety-one".