31000121523 has 32 divisors (see below), whose sum is σ = 52864627200. Its totient is φ = 17586898848.

The previous prime is 31000121521. The next prime is 31000121557. The reversal of 31000121523 is 32512100013.

It is not a de Polignac number, because 31000121523 - 2¹ = 31000121521 is a prime.

It is a super-2 number, since 2×31000121523² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31000121496 and 31000121505.

It is not an unprimeable number, because it can be changed into a prime (31000121521) 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 31 ways as a sum of consecutive naturals, for example, 563736 + ... + 616277.

It is an arithmetic number, because the mean of its divisors is an integer number (1652019600).

Almost surely, 2^31000121523 is an apocalyptic number.

31000121523 is a deficient number, since it is larger than the sum of its proper divisors (21864505677).

31000121523 is a wasteful number, since it uses less digits than its factorization.

31000121523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1180168 (or 1180162 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

Adding to 31000121523 its reverse (32512100013), we get a palindrome (63512221536).

The spelling of 31000121523 in words is "thirty-one billion, one hundred twenty-one thousand, five hundred twenty-three".