20815059309 has 16 divisors (see below), whose sum is σ = 30728340480. Its totient is φ = 12426899760.

The previous prime is 20815059299. The next prime is 20815059311. The reversal of 20815059309 is 90395051802.

It is a de Polignac number, because none of the positive numbers 2^k-20815059309 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20815059359) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4704949 + ... + 4709370.

It is an arithmetic number, because the mean of its divisors is an integer number (1920521280).

Almost surely, 2^20815059309 is an apocalyptic number.

It is an amenable number.

20815059309 is a deficient number, since it is larger than the sum of its proper divisors (9913281171).

20815059309 is a wasteful number, since it uses less digits than its factorization.

20815059309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9414400.

The product of its (nonzero) digits is 97200, while the sum is 42.

The spelling of 20815059309 in words is "twenty billion, eight hundred fifteen million, fifty-nine thousand, three hundred nine".