638019691669 has 8 divisors (see below), whose sum is σ = 640364801760. Its totient is φ = 635675220336.

The previous prime is 638019691637. The next prime is 638019691681. The reversal of 638019691669 is 966196910836.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 638019691669 - 2⁵ = 638019691637 is a prime.

It is a super-2 number, since 2×638019691669² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 638019691669.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638019691469) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1889874 + ... + 2201740.

It is an arithmetic number, because the mean of its divisors is an integer number (80045600220).

Almost surely, 2^638019691669 is an apocalyptic number.

It is an amenable number.

638019691669 is a deficient number, since it is larger than the sum of its proper divisors (2345110091).

638019691669 is a wasteful number, since it uses less digits than its factorization.

638019691669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319379.

The product of its (nonzero) digits is 22674816, while the sum is 64.

The spelling of 638019691669 in words is "six hundred thirty-eight billion, nineteen million, six hundred ninety-one thousand, six hundred sixty-nine".