20502511609 has 4 divisors (see below), whose sum is σ = 20617050960. Its totient is φ = 20387972260.

The previous prime is 20502511483. The next prime is 20502511613. The reversal of 20502511609 is 90611520502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 90611520502 = 2 ⋅45305760251.

It is a cyclic number.

It is not a de Polignac number, because 20502511609 - 2⁹ = 20502511097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20502511639) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57269407 + ... + 57269764.

It is an arithmetic number, because the mean of its divisors is an integer number (5154262740).

Almost surely, 2^20502511609 is an apocalyptic number.

It is an amenable number.

20502511609 is a deficient number, since it is larger than the sum of its proper divisors (114539351).

20502511609 is a wasteful number, since it uses less digits than its factorization.

20502511609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114539350.

The product of its (nonzero) digits is 5400, while the sum is 31.

The spelling of 20502511609 in words is "twenty billion, five hundred two million, five hundred eleven thousand, six hundred nine".