638460827461 has 4 divisors (see below), whose sum is σ = 638464638924. Its totient is φ = 638457016000.

The previous prime is 638460827441. The next prime is 638460827479. The reversal of 638460827461 is 164728064836.

It is a happy number.

638460827461 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 499115403361 + 139345424100 = 706481^2 + 373290^2 .

It is a cyclic number.

It is not a de Polignac number, because 638460827461 - 2¹¹ = 638460825413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638460827441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1642330 + ... + 1993531.

It is an arithmetic number, because the mean of its divisors is an integer number (159616159731).

Almost surely, 2^638460827461 is an apocalyptic number.

It is an amenable number.

638460827461 is a deficient number, since it is larger than the sum of its proper divisors (3811463).

638460827461 is a wasteful number, since it uses less digits than its factorization.

638460827461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3811462.

The product of its (nonzero) digits is 9289728, while the sum is 55.

The spelling of 638460827461 in words is "six hundred thirty-eight billion, four hundred sixty million, eight hundred twenty-seven thousand, four hundred sixty-one".