18918920811 has 16 divisors (see below), whose sum is σ = 28830873600. Its totient is φ = 10810046208.

The previous prime is 18918920789. The next prime is 18918920861. The reversal of 18918920811 is 11802981981.

It is a happy number.

It is not a de Polignac number, because 18918920811 - 2⁹ = 18918920299 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18918920861) 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, 421510 + ... + 464228.

It is an arithmetic number, because the mean of its divisors is an integer number (1801929600).

Almost surely, 2^18918920811 is an apocalyptic number.

18918920811 is a deficient number, since it is larger than the sum of its proper divisors (9911952789).

18918920811 is a wasteful number, since it uses less digits than its factorization.

18918920811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63818.

The product of its (nonzero) digits is 82944, while the sum is 48.

The spelling of 18918920811 in words is "eighteen billion, nine hundred eighteen million, nine hundred twenty thousand, eight hundred eleven".