18081187777 has 16 divisors (see below), whose sum is σ = 20441773440. Its totient is φ = 15899127552.

The previous prime is 18081187723. The next prime is 18081187783. The reversal of 18081187777 is 77778118081.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18081187777 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18081187717) 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, 520902 + ... + 554527.

It is an arithmetic number, because the mean of its divisors is an integer number (1277610840).

Almost surely, 2^18081187777 is an apocalyptic number.

18081187777 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

18081187777 is a deficient number, since it is larger than the sum of its proper divisors (2360585663).

18081187777 is a wasteful number, since it uses less digits than its factorization.

18081187777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1075512.

The product of its (nonzero) digits is 1229312, while the sum is 55.

The spelling of 18081187777 in words is "eighteen billion, eighty-one million, one hundred eighty-seven thousand, seven hundred seventy-seven".