20155561111 has 8 divisors (see below), whose sum is σ = 23262996384. Its totient is φ = 17105143200.

The previous prime is 20155561109. The next prime is 20155561187. The reversal of 20155561111 is 11116555102.

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 20155561111 - 2¹ = 20155561109 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20155561111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20155561511) 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, 14253580 + ... + 14254993.

It is an arithmetic number, because the mean of its divisors is an integer number (2907874548).

Almost surely, 2^20155561111 is an apocalyptic number.

20155561111 is a deficient number, since it is larger than the sum of its proper divisors (3107435273).

20155561111 is a wasteful number, since it uses less digits than its factorization.

20155561111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28508681.

The product of its (nonzero) digits is 1500, while the sum is 28.

The spelling of 20155561111 in words is "twenty billion, one hundred fifty-five million, five hundred sixty-one thousand, one hundred eleven".