18947101977 has 12 divisors (see below), whose sum is σ = 27392728740. Its totient is φ = 12620004768.

The previous prime is 18947101951. The next prime is 18947101991. The reversal of 18947101977 is 77910174981.

It is a happy number.

18947101977 is a `hidden beast` number, since 1 + 89 + 471 + 0 + 1 + 97 + 7 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1592728281 + 17354373696 = 39909^2 + 131736^2 .

It is not a de Polignac number, because 18947101977 - 2¹⁵ = 18947069209 is a prime.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (18947101577) 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, 939178 + ... + 959139.

It is an arithmetic number, because the mean of its divisors is an integer number (2282727395).

Almost surely, 2^18947101977 is an apocalyptic number.

It is an amenable number.

18947101977 is a deficient number, since it is larger than the sum of its proper divisors (8445626763).

18947101977 is a wasteful number, since it uses less digits than its factorization.

18947101977 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1899432 (or 1899429 counting only the distinct ones).

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

The spelling of 18947101977 in words is "eighteen billion, nine hundred forty-seven million, one hundred one thousand, nine hundred seventy-seven".