1638107081 has 16 divisors (see below), whose sum is σ = 1843209984. Its totient is φ = 1444474944.

The previous prime is 1638107017. The next prime is 1638107113. The reversal of 1638107081 is 1807018361.

It is a cyclic number.

It is not a de Polignac number, because 1638107081 - 2⁶ = 1638107017 is a prime.

It is a super-2 number, since 2×1638107081² = 5366789617644681122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1638107011) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 259100 + ... + 265346.

It is an arithmetic number, because the mean of its divisors is an integer number (115200624).

Almost surely, 2^1638107081 is an apocalyptic number.

It is an amenable number.

1638107081 is a deficient number, since it is larger than the sum of its proper divisors (205102903).

1638107081 is a wasteful number, since it uses less digits than its factorization.

1638107081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7160.

The product of its (nonzero) digits is 8064, while the sum is 35.

The square root of 1638107081 is about 40473.5355633777. The cubic root of 1638107081 is about 1178.8198199856.

The spelling of 1638107081 in words is "one billion, six hundred thirty-eight million, one hundred seven thousand, eighty-one".