31231120023405 has 20 divisors (see below), whose sum is σ = 55984674413052. Its totient is φ = 16656597345600.

The previous prime is 31231120023371. The next prime is 31231120023407. The reversal of 31231120023405 is 50432002113213.

31231120023405 is a `hidden beast` number, since 3 + 1 + 2 + 31 + 1 + 200 + 23 + 405 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 10187963875881 + 21043156147524 = 3191859^2 + 4587282^2 .

It is not a de Polignac number, because 31231120023405 - 2¹¹ = 31231120021357 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31231120023407) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 38556937896 + ... + 38556938705.

Almost surely, 2^{31231120023405} is an apocalyptic number.

It is an amenable number.

31231120023405 is a deficient number, since it is larger than the sum of its proper divisors (24753554389647).

31231120023405 is an equidigital number, since it uses as much as digits as its factorization.

31231120023405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77113876618 (or 77113876609 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

Adding to 31231120023405 its reverse (50432002113213), we get a palindrome (81663122136618).

The spelling of 31231120023405 in words is "thirty-one trillion, two hundred thirty-one billion, one hundred twenty million, twenty-three thousand, four hundred five".