638613620655 has 8 divisors (see below), whose sum is σ = 1021781793072. Its totient is φ = 340593931008.

The previous prime is 638613620633. The next prime is 638613620677. The reversal of 638613620655 is 556026316836.

638613620655 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (638613620633) and next prime (638613620677).

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

It is not a de Polignac number, because 638613620655 - 2¹¹ = 638613618607 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 638613620598 and 638613620607.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21287120674 + ... + 21287120703.

It is an arithmetic number, because the mean of its divisors is an integer number (127722724134).

Almost surely, 2^638613620655 is an apocalyptic number.

638613620655 is a deficient number, since it is larger than the sum of its proper divisors (383168172417).

638613620655 is a wasteful number, since it uses less digits than its factorization.

638613620655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42574241385.

The product of its (nonzero) digits is 4665600, while the sum is 51.

The spelling of 638613620655 in words is "six hundred thirty-eight billion, six hundred thirteen million, six hundred twenty thousand, six hundred fifty-five".