42999991 has 4 divisors (see below), whose sum is σ = 43027000. Its totient is φ = 42972984.

The previous prime is 42999977. The next prime is 43000019. The reversal of 42999991 is 19999924.

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 42999991 - 2¹¹ = 42997943 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42999911) 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, 10956 + ... + 14353.

It is an arithmetic number, because the mean of its divisors is an integer number (10756750).

Almost surely, 2^42999991 is an apocalyptic number.

42999991 is a deficient number, since it is larger than the sum of its proper divisors (27009).

42999991 is a wasteful number, since it uses less digits than its factorization.

42999991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27008.

The product of its digits is 472392, while the sum is 52.

The square root of 42999991 is about 6557.4378380584. The cubic root of 42999991 is about 350.3397815964.

The spelling of 42999991 in words is "forty-two million, nine hundred ninety-nine thousand, nine hundred ninety-one".