1638020136450 has 96 divisors (see below), whose sum is σ = 4095161892864. Its totient is φ = 433272248640.

The previous prime is 1638020136443. The next prime is 1638020136479. The reversal of 1638020136450 is 546310208361.

It is a super-3 number, since 3×1638020136450³ (a number of 38 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1638020136399 and 1638020136408.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 164339367 + ... + 164349333.

It is an arithmetic number, because the mean of its divisors is an integer number (42657936384).

Almost surely, 2^{1638020136450} is an apocalyptic number.

1638020136450 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1638020136450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2047580946432).

1638020136450 is an abundant number, since it is smaller than the sum of its proper divisors (2457141756414).

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

1638020136450 is a wasteful number, since it uses less digits than its factorization.

1638020136450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18736 (or 18731 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 39.

The spelling of 1638020136450 in words is "one trillion, six hundred thirty-eight billion, twenty million, one hundred thirty-six thousand, four hundred fifty".