155781111811 has 4 divisors (see below), whose sum is σ = 167764274272. Its totient is φ = 143797949352.

The previous prime is 155781111799. The next prime is 155781111841. The reversal of 155781111811 is 118111187551.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 155781111811 - 2⁷ = 155781111683 is a prime.

It is a super-3 number, since 3×155781111811³ (a number of 35 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155781111841) 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, 5991581211 + ... + 5991581236.

It is an arithmetic number, because the mean of its divisors is an integer number (41941068568).

Almost surely, 2^155781111811 is an apocalyptic number.

155781111811 is a deficient number, since it is larger than the sum of its proper divisors (11983162461).

155781111811 is a wasteful number, since it uses less digits than its factorization.

155781111811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11983162460.

The product of its digits is 11200, while the sum is 40.

The spelling of 155781111811 in words is "one hundred fifty-five billion, seven hundred eighty-one million, one hundred eleven thousand, eight hundred eleven".