42638591 has 4 divisors (see below), whose sum is σ = 43178400. Its totient is φ = 42098784.

The previous prime is 42638543. The next prime is 42638593. The reversal of 42638591 is 19583624.

It is a happy number.

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

It is a de Polignac number, because none of the positive numbers 2^k-42638591 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 (42638593) 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, 269786 + ... + 269943.

It is an arithmetic number, because the mean of its divisors is an integer number (10794600).

Almost surely, 2^42638591 is an apocalyptic number.

42638591 is a deficient number, since it is larger than the sum of its proper divisors (539809).

42638591 is an equidigital number, since it uses as much as digits as its factorization.

42638591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 539808.

The product of its digits is 51840, while the sum is 38.

The square root of 42638591 is about 6529.8231982191. The cubic root of 42638591 is about 349.3555242210.

The spelling of 42638591 in words is "forty-two million, six hundred thirty-eight thousand, five hundred ninety-one".