1638906041 has 2 divisors, whose sum is σ = 1638906042. Its totient is φ = 1638906040.

The previous prime is 1638906037. The next prime is 1638906043. The reversal of 1638906041 is 1406098361.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 866066041 + 772840000 = 29429^2 + 27800^2 .

It is an emirp because it is prime and its reverse (1406098361) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1638906041 - 2² = 1638906037 is a prime.

It is a super-2 number, since 2×1638906041² = 5372026022452587362, which contains 22 as substring.

Together with 1638906043, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 1638905986 and 1638906004.

It is not a weakly prime, because it can be changed into another prime (1638906043) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 819453020 + 819453021.

It is an arithmetic number, because the mean of its divisors is an integer number (819453021).

Almost surely, 2^1638906041 is an apocalyptic number.

It is an amenable number.

1638906041 is a deficient number, since it is larger than the sum of its proper divisors (1).

1638906041 is an equidigital number, since it uses as much as digits as its factorization.

1638906041 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 38.

The square root of 1638906041 is about 40483.4045134546. The cubic root of 1638906041 is about 1179.0114388801.

The spelling of 1638906041 in words is "one billion, six hundred thirty-eight million, nine hundred six thousand, forty-one".