42121361831 has 4 divisors (see below), whose sum is σ = 42258565272. Its totient is φ = 41984158392.

The previous prime is 42121361797. The next prime is 42121361851. The reversal of 42121361831 is 13816312124.

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 42121361831 - 2¹⁰ = 42121360807 is a prime.

It is a super-2 number, since 2×42121361831² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42121361851) 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, 68601260 + ... + 68601873.

It is an arithmetic number, because the mean of its divisors is an integer number (10564641318).

Almost surely, 2^42121361831 is an apocalyptic number.

42121361831 is a deficient number, since it is larger than the sum of its proper divisors (137203441).

42121361831 is a wasteful number, since it uses less digits than its factorization.

42121361831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137203440.

The product of its digits is 6912, while the sum is 32.

Adding to 42121361831 its reverse (13816312124), we get a palindrome (55937673955).

The spelling of 42121361831 in words is "forty-two billion, one hundred twenty-one million, three hundred sixty-one thousand, eight hundred thirty-one".