18774047781 has 32 divisors (see below), whose sum is σ = 29033303040. Its totient is φ = 11967476400.

The previous prime is 18774047771. The next prime is 18774047783.

18774047781 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 18774047781 - 2⁵ = 18774047749 is a prime.

It is a super-2 number, since 2×18774047781² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18774047783) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3059086 + ... + 3065216.

It is an arithmetic number, because the mean of its divisors is an integer number (907290720).

Almost surely, 2^18774047781 is an apocalyptic number.

It is an amenable number.

18774047781 is a deficient number, since it is larger than the sum of its proper divisors (10259255259).

18774047781 is a wasteful number, since it uses less digits than its factorization.

18774047781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11094 (or 11088 counting only the distinct ones).

The product of its (nonzero) digits is 2458624, while the sum is 54.

The spelling of 18774047781 in words is "eighteen billion, seven hundred seventy-four million, forty-seven thousand, seven hundred eighty-one".