20042135231 has 4 divisors (see below), whose sum is σ = 20060208600. Its totient is φ = 20024061864.

The previous prime is 20042135177. The next prime is 20042135233. The reversal of 20042135231 is 13253124002.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13253124002 = 2 ⋅6626562001.

It is a cyclic number.

It is not a de Polignac number, because 20042135231 - 2³⁰ = 18968393407 is a prime.

It is a super-2 number, since 2×20042135231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20042135197 and 20042135206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20042135233) 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, 9035021 + ... + 9037238.

It is an arithmetic number, because the mean of its divisors is an integer number (5015052150).

Almost surely, 2^20042135231 is an apocalyptic number.

20042135231 is a deficient number, since it is larger than the sum of its proper divisors (18073369).

20042135231 is a wasteful number, since it uses less digits than its factorization.

20042135231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18073368.

The product of its (nonzero) digits is 1440, while the sum is 23.

Adding to 20042135231 its reverse (13253124002), we get a palindrome (33295259233).

The spelling of 20042135231 in words is "twenty billion, forty-two million, one hundred thirty-five thousand, two hundred thirty-one".