18191077947 has 12 divisors (see below), whose sum is σ = 30029716080. Its totient is φ = 10394901648.

The previous prime is 18191077903. The next prime is 18191077963. The reversal of 18191077947 is 74977019181.

It is a happy number.

It is not a de Polignac number, because 18191077947 - 2⁷ = 18191077819 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18191077893 and 18191077902.

It is not an unprimeable number, because it can be changed into a prime (18191077997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 144373572 + ... + 144373697.

It is an arithmetic number, because the mean of its divisors is an integer number (2502476340).

Almost surely, 2^18191077947 is an apocalyptic number.

18191077947 is a deficient number, since it is larger than the sum of its proper divisors (11838638133).

18191077947 is a wasteful number, since it uses less digits than its factorization.

18191077947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 288747282 (or 288747279 counting only the distinct ones).

The product of its (nonzero) digits is 889056, while the sum is 54.

It can be divided in two parts, 1819107794 and 7, that added together give a square (1819107801 = 42651²).

The spelling of 18191077947 in words is "eighteen billion, one hundred ninety-one million, seventy-seven thousand, nine hundred forty-seven".