20502312312509 has 4 divisors (see below), whose sum is σ = 20505936555804. Its totient is φ = 20498688069216.

The previous prime is 20502312312421. The next prime is 20502312312533. The reversal of 20502312312509 is 90521321320502.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1191754305625 + 19310558006884 = 1091675^2 + 4394378^2 .

It is a cyclic number.

It is not a de Polignac number, because 20502312312509 - 2²⁰ = 20502311263933 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20502312312709) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1812113162 + ... + 1812124475.

It is an arithmetic number, because the mean of its divisors is an integer number (5126484138951).

Almost surely, 2^{20502312312509} is an apocalyptic number.

It is an amenable number.

20502312312509 is a deficient number, since it is larger than the sum of its proper divisors (3624243295).

20502312312509 is an equidigital number, since it uses as much as digits as its factorization.

20502312312509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3624243294.

The product of its (nonzero) digits is 32400, while the sum is 35.

The spelling of 20502312312509 in words is "twenty trillion, five hundred two billion, three hundred twelve million, three hundred twelve thousand, five hundred nine".