1641871620864 has 432 divisors, whose sum is σ = 5024786457600. Its totient is φ = 528800845824.

The previous prime is 1641871620859. The next prime is 1641871620919. The reversal of 1641871620864 is 4680261781461.

1641871620864 is a `hidden beast` number, since 1 + 6 + 4 + 1 + 8 + 7 + 1 + 620 + 8 + 6 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (432).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 1641871620864.

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, 1580241657 + ... + 1580242695.

Almost surely, 2^{1641871620864} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1641871620864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2512393228800).

1641871620864 is an abundant number, since it is smaller than the sum of its proper divisors (3382914836736).

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

1641871620864 is a wasteful number, since it uses less digits than its factorization.

1641871620864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1305 (or 1248 counting only the distinct ones).

The product of its (nonzero) digits is 3096576, while the sum is 54.

The spelling of 1641871620864 in words is "one trillion, six hundred forty-one billion, eight hundred seventy-one million, six hundred twenty thousand, eight hundred sixty-four".