1638906011 has 2 divisors, whose sum is σ = 1638906012. Its totient is φ = 1638906010.

The previous prime is 1638906007. The next prime is 1638906037. The reversal of 1638906011 is 1106098361.

It is a weak prime.

It is an emirp because it is prime and its reverse (1106098361) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1638906011 - 2² = 1638906007 is a prime.

It is not a weakly prime, because it can be changed into another prime (1638906041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 819453005 + 819453006.

It is an arithmetic number, because the mean of its divisors is an integer number (819453006).

Almost surely, 2^1638906011 is an apocalyptic number.

1638906011 is a deficient number, since it is larger than the sum of its proper divisors (1).

1638906011 is an equidigital number, since it uses as much as digits as its factorization.

1638906011 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 1638906011 is about 40483.4041429324. The cubic root of 1638906011 is about 1179.0114316863.

The spelling of 1638906011 in words is "one billion, six hundred thirty-eight million, nine hundred six thousand, eleven".