31520004123 has 4 divisors (see below), whose sum is σ = 42026672168. Its totient is φ = 21013336080.

The previous prime is 31520004121. The next prime is 31520004161. The reversal of 31520004123 is 32140002513.

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

It is not a de Polignac number, because 31520004123 - 2¹ = 31520004121 is a prime.

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 31520004123.

It is not an unprimeable number, because it can be changed into a prime (31520004121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5253334018 + ... + 5253334023.

It is an arithmetic number, because the mean of its divisors is an integer number (10506668042).

Almost surely, 2^31520004123 is an apocalyptic number.

31520004123 is a deficient number, since it is larger than the sum of its proper divisors (10506668045).

31520004123 is a wasteful number, since it uses less digits than its factorization.

31520004123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10506668044.

The product of its (nonzero) digits is 720, while the sum is 21.

Adding to 31520004123 its reverse (32140002513), we get a palindrome (63660006636).

The spelling of 31520004123 in words is "thirty-one billion, five hundred twenty million, four thousand, one hundred twenty-three".