20407405231 has 4 divisors (see below), whose sum is σ = 20905146864. Its totient is φ = 19909663600.

The previous prime is 20407405219. The next prime is 20407405283. The reversal of 20407405231 is 13250470402.

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 20407405231 - 2¹¹ = 20407403183 is a prime.

It is a super-2 number, since 2×20407405231² (a number of 21 digits) contains 22 as substring.

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 20407405231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20407405831) 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, 248870755 + ... + 248870836.

It is an arithmetic number, because the mean of its divisors is an integer number (5226286716).

Almost surely, 2^20407405231 is an apocalyptic number.

20407405231 is a deficient number, since it is larger than the sum of its proper divisors (497741633).

20407405231 is an equidigital number, since it uses as much as digits as its factorization.

20407405231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 497741632.

The product of its (nonzero) digits is 6720, while the sum is 28.

Adding to 20407405231 its reverse (13250470402), we get a palindrome (33657875633).

The spelling of 20407405231 in words is "twenty billion, four hundred seven million, four hundred five thousand, two hundred thirty-one".