18920277601 has 9 divisors (see below), whose sum is σ = 19216244691. Its totient is φ = 18628807032.

The previous prime is 18920277599. The next prime is 18920277613. The reversal of 18920277601 is 10677202981.

The square root of 18920277601 is 137551.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 9766380625 + 9153896976 = 98825^2 + 95676^2 .

It is not a de Polignac number, because 18920277601 - 2¹ = 18920277599 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18920277401) 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 8 ways as a sum of consecutive naturals, for example, 9214891 + ... + 9216943.

It is an arithmetic number, because the mean of its divisors is an integer number (2135138299).

Almost surely, 2^18920277601 is an apocalyptic number.

18920277601 is the 137551-st square number.

18920277601 is the 68776-th centered octagonal number.

It is an amenable number.

18920277601 is a deficient number, since it is larger than the sum of its proper divisors (295967090).

18920277601 is an frugal number, since it uses more digits than its factorization.

18920277601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4240 (or 2120 counting only the distinct ones).

The product of its (nonzero) digits is 84672, while the sum is 43.

The spelling of 18920277601 in words is "eighteen billion, nine hundred twenty million, two hundred seventy-seven thousand, six hundred one".