42781591 has 4 divisors (see below), whose sum is σ = 42795184. Its totient is φ = 42768000.

The previous prime is 42781589. The next prime is 42781619. The reversal of 42781591 is 19518724.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 42781591 - 2¹ = 42781589 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 42781591.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42781561) 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, 631 + ... + 9271.

It is an arithmetic number, because the mean of its divisors is an integer number (10698796).

Almost surely, 2^42781591 is an apocalyptic number.

42781591 is a deficient number, since it is larger than the sum of its proper divisors (13593).

42781591 is an equidigital number, since it uses as much as digits as its factorization.

42781591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13592.

The product of its digits is 20160, while the sum is 37.

The square root of 42781591 is about 6540.7637933196. The cubic root of 42781591 is about 349.7456410423.

The spelling of 42781591 in words is "forty-two million, seven hundred eighty-one thousand, five hundred ninety-one".