1638000017820 has 72 divisors (see below), whose sum is σ = 5042758300944. Its totient is φ = 430280598528.

The previous prime is 1638000017813. The next prime is 1638000017833. The reversal of 1638000017820 is 287100008361.

1638000017820 is a `hidden beast` number, since 1 + 638 + 0 + 0 + 0 + 0 + 17 + 8 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

1638000017820 is a modest number, since divided by 17820 gives 16380 as remainder.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 67898389 + ... + 67922508.

Almost surely, 2^{1638000017820} is an apocalyptic number.

1638000017820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1638000017820 is an abundant number, since it is smaller than the sum of its proper divisors (3404758283124).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1638000017820 is a wasteful number, since it uses less digits than its factorization.

1638000017820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135820979 (or 135820974 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The spelling of 1638000017820 in words is "one trillion, six hundred thirty-eight billion, seventeen thousand, eight hundred twenty".