638618071 has 16 divisors (see below), whose sum is σ = 797730304. Its totient is φ = 497733984.

The previous prime is 638618059. The next prime is 638618081. The reversal of 638618071 is 170816836.

It is a cyclic number.

It is not a de Polignac number, because 638618071 - 2⁹ = 638617559 is a prime.

It is a super-2 number, since 2×638618071² = 815666081215522082, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638618081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46275 + ... + 58468.

It is an arithmetic number, because the mean of its divisors is an integer number (49858144).

Almost surely, 2^638618071 is an apocalyptic number.

638618071 is a deficient number, since it is larger than the sum of its proper divisors (159112233).

638618071 is a wasteful number, since it uses less digits than its factorization.

638618071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104830.

The product of its (nonzero) digits is 48384, while the sum is 40.

The square root of 638618071 is about 25270.8937515079. The cubic root of 638618071 is about 861.1531632504.

The spelling of 638618071 in words is "six hundred thirty-eight million, six hundred eighteen thousand, seventy-one".