2157820601664 has 672 divisors, whose sum is σ = 7307704943616. Its totient is φ = 556826296320.

The previous prime is 2157820601663. The next prime is 2157820601701. The reversal of 2157820601664 is 4661060287512.

It is a tau number, because it is divible by the number of its divisors (672).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2157820601663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1663700664 + ... + 1663701960.

It is an arithmetic number, because the mean of its divisors is an integer number (10874560928).

Almost surely, 2^{2157820601664} is an apocalyptic number.

2157820601664 is a gapful number since it is divisible by the number (24) 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 2157820601664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3653852471808).

2157820601664 is an abundant number, since it is smaller than the sum of its proper divisors (5149884341952).

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

2157820601664 is a wasteful number, since it uses less digits than its factorization.

2157820601664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1623 (or 1606 counting only the distinct ones).

The product of its (nonzero) digits is 967680, while the sum is 48.

The spelling of 2157820601664 in words is "two trillion, one hundred fifty-seven billion, eight hundred twenty million, six hundred one thousand, six hundred sixty-four".