20156686909 has 8 divisors (see below), whose sum is σ = 20322450720. Its totient is φ = 19991103600.

The previous prime is 20156686889. The next prime is 20156686919. The reversal of 20156686909 is 90968665102.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20156686909 - 2⁹ = 20156686397 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 (20156686919) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 183882 + ... + 272260.

It is an arithmetic number, because the mean of its divisors is an integer number (2540306340).

Almost surely, 2^20156686909 is an apocalyptic number.

It is an amenable number.

20156686909 is a deficient number, since it is larger than the sum of its proper divisors (165763811).

20156686909 is a wasteful number, since it uses less digits than its factorization.

20156686909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90251.

The product of its (nonzero) digits is 1399680, while the sum is 52.

The spelling of 20156686909 in words is "twenty billion, one hundred fifty-six million, six hundred eighty-six thousand, nine hundred nine".