638546360477761 has 4 divisors (see below), whose sum is σ = 659144630170624. Its totient is φ = 617948090784900.

The previous prime is 638546360477759. The next prime is 638546360477777. The reversal of 638546360477761 is 167774063645836.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 638546360477761 - 2¹ = 638546360477759 is a prime.

It is not an unprimeable number, because it can be changed into a prime (638546360477731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10299134846385 + ... + 10299134846446.

It is an arithmetic number, because the mean of its divisors is an integer number (164786157542656).

Almost surely, 2^{638546360477761} is an apocalyptic number.

It is an amenable number.

638546360477761 is a deficient number, since it is larger than the sum of its proper divisors (20598269692863).

638546360477761 is a wasteful number, since it uses less digits than its factorization.

638546360477761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20598269692862.

The product of its (nonzero) digits is 2560481280, while the sum is 73.

The spelling of 638546360477761 in words is "six hundred thirty-eight trillion, five hundred forty-six billion, three hundred sixty million, four hundred seventy-seven thousand, seven hundred sixty-one".