20402331231 has 4 divisors (see below), whose sum is σ = 27203108312. Its totient is φ = 13601554152.

The previous prime is 20402331223. The next prime is 20402331239. The reversal of 20402331231 is 13213320402.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (20402331223) and next prime (20402331239).

It is not a de Polignac number, because 20402331231 - 2³ = 20402331223 is a prime.

It is a super-2 number, since 2×20402331231² (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 = 20402331198 and 20402331207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20402331239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3400388536 + ... + 3400388541.

It is an arithmetic number, because the mean of its divisors is an integer number (6800777078).

Almost surely, 2^20402331231 is an apocalyptic number.

20402331231 is a deficient number, since it is larger than the sum of its proper divisors (6800777081).

20402331231 is an equidigital number, since it uses as much as digits as its factorization.

20402331231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6800777080.

The product of its (nonzero) digits is 864, while the sum is 21.

Adding to 20402331231 its reverse (13213320402), we get a palindrome (33615651633).

The spelling of 20402331231 in words is "twenty billion, four hundred two million, three hundred thirty-one thousand, two hundred thirty-one".