20509019858 has 16 divisors (see below), whose sum is σ = 32066551104. Its totient is φ = 9828442800.

The previous prime is 20509019857. The next prime is 20509019887. The reversal of 20509019858 is 85891090502.

It is not an unprimeable number, because it can be changed into a prime (20509019857) 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 7 ways as a sum of consecutive naturals, for example, 2063318 + ... + 2073233.

It is an arithmetic number, because the mean of its divisors is an integer number (2004159444).

Almost surely, 2^20509019858 is an apocalyptic number.

20509019858 is a deficient number, since it is larger than the sum of its proper divisors (11557531246).

20509019858 is a wasteful number, since it uses less digits than its factorization.

20509019858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4136657.

The product of its (nonzero) digits is 259200, while the sum is 47.

The spelling of 20509019858 in words is "twenty billion, five hundred nine million, nineteen thousand, eight hundred fifty-eight".