638371421495 has 32 divisors (see below), whose sum is σ = 783030067200. Its totient is φ = 499500578304.

The previous prime is 638371421461. The next prime is 638371421497. The reversal of 638371421495 is 594124173836.

It is a cyclic number.

It is not a de Polignac number, because 638371421495 - 2⁸ = 638371421239 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638371421497) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 137607386 + ... + 137612024.

It is an arithmetic number, because the mean of its divisors is an integer number (24469689600).

Almost surely, 2^638371421495 is an apocalyptic number.

638371421495 is a deficient number, since it is larger than the sum of its proper divisors (144658645705).

638371421495 is a wasteful number, since it uses less digits than its factorization.

638371421495 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7919.

The product of its digits is 4354560, while the sum is 53.

The spelling of 638371421495 in words is "six hundred thirty-eight billion, three hundred seventy-one million, four hundred twenty-one thousand, four hundred ninety-five".