42347991 has 32 divisors (see below), whose sum is σ = 68935680. Its totient is φ = 22597344.

The previous prime is 42347989. The next prime is 42348013. The reversal of 42347991 is 19974324.

It is not a de Polignac number, because 42347991 - 2¹ = 42347989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42347951) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19750 + ... + 21788.

It is an arithmetic number, because the mean of its divisors is an integer number (2154240).

Almost surely, 2^42347991 is an apocalyptic number.

42347991 is a deficient number, since it is larger than the sum of its proper divisors (26587689).

42347991 is a wasteful number, since it uses less digits than its factorization.

42347991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2115.

The product of its digits is 54432, while the sum is 39.

The square root of 42347991 is about 6507.5334036792. The cubic root of 42347991 is about 348.5600458348.

The spelling of 42347991 in words is "forty-two million, three hundred forty-seven thousand, nine hundred ninety-one".