1643749936128 has 440 divisors, whose sum is σ = 5094949330944. Its totient is φ = 527308185600.

The previous prime is 1643749936109. The next prime is 1643749936139. The reversal of 1643749936128 is 8216399473461.

1643749936128 is a `hidden beast` number, since 1 + 6 + 4 + 3 + 7 + 4 + 9 + 9 + 3 + 612 + 8 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 491109751 + ... + 491113097.

Almost surely, 2^{1643749936128} is an apocalyptic number.

1643749936128 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1643749936128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2547474665472).

1643749936128 is an abundant number, since it is smaller than the sum of its proper divisors (3451199394816).

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

1643749936128 is a wasteful number, since it uses less digits than its factorization.

1643749936128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3601 (or 3574 counting only the distinct ones).

The product of its digits is 47029248, while the sum is 63.

The spelling of 1643749936128 in words is "one trillion, six hundred forty-three billion, seven hundred forty-nine million, nine hundred thirty-six thousand, one hundred twenty-eight".