42591631 has 4 divisors (see below), whose sum is σ = 43175152. Its totient is φ = 42008112.

The previous prime is 42591617. The next prime is 42591643. The reversal of 42591631 is 13619524.

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 42591631 - 2¹⁹ = 42067343 is a prime.

It is a super-2 number, since 2×42591631² = 3628094062480322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 42591593 and 42591602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42591931) 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, 291651 + ... + 291796.

It is an arithmetic number, because the mean of its divisors is an integer number (10793788).

Almost surely, 2^42591631 is an apocalyptic number.

42591631 is a deficient number, since it is larger than the sum of its proper divisors (583521).

42591631 is an equidigital number, since it uses as much as digits as its factorization.

42591631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 583520.

The product of its digits is 6480, while the sum is 31.

The square root of 42591631 is about 6526.2263981569. The cubic root of 42591631 is about 349.2272229057.

The spelling of 42591631 in words is "forty-two million, five hundred ninety-one thousand, six hundred thirty-one".