638867400446 has 32 divisors (see below), whose sum is σ = 1047041372160. Its totient is φ = 289944093600.

The previous prime is 638867400443. The next prime is 638867400499. The reversal of 638867400446 is 644004768836.

It is a junction number, because it is equal to n+sod(n) for n = 638867400391 and 638867400400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638867400443) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40023815 + ... + 40039773.

It is an arithmetic number, because the mean of its divisors is an integer number (32720042880).

Almost surely, 2^638867400446 is an apocalyptic number.

638867400446 is a deficient number, since it is larger than the sum of its proper divisors (408173971714).

638867400446 is a wasteful number, since it uses less digits than its factorization.

638867400446 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18680.

The product of its (nonzero) digits is 18579456, while the sum is 56.

The spelling of 638867400446 in words is "six hundred thirty-eight billion, eight hundred sixty-seven million, four hundred thousand, four hundred forty-six".