1638225877 has 2 divisors, whose sum is σ = 1638225878. Its totient is φ = 1638225876.

The previous prime is 1638225833. The next prime is 1638225947. The reversal of 1638225877 is 7785228361.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1208327121 + 429898756 = 34761^2 + 20734^2 .

It is a cyclic number.

It is not a de Polignac number, because 1638225877 - 2²³ = 1629837269 is a prime.

It is a super-3 number, since 3×1638225877³ (a number of 29 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1638225877.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1638225817) 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 as a sum of consecutive naturals, namely, 819112938 + 819112939.

It is an arithmetic number, because the mean of its divisors is an integer number (819112939).

Almost surely, 2^1638225877 is an apocalyptic number.

It is an amenable number.

1638225877 is a deficient number, since it is larger than the sum of its proper divisors (1).

1638225877 is an equidigital number, since it uses as much as digits as its factorization.

1638225877 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1128960, while the sum is 49.

The square root of 1638225877 is about 40475.0031130326. The cubic root of 1638225877 is about 1178.8483154150.

The spelling of 1638225877 in words is "one billion, six hundred thirty-eight million, two hundred twenty-five thousand, eight hundred seventy-seven".