1621898711928 has 768 divisors, whose sum is σ = 5559484170240. Its totient is φ = 437110732800.

The previous prime is 1621898711921. The next prime is 1621898711941. The reversal of 1621898711928 is 8291178981261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621898711921) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 484581151 + ... + 484584497.

It is an arithmetic number, because the mean of its divisors is an integer number (7238911680).

Almost surely, 2^{1621898711928} is an apocalyptic number.

1621898711928 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 1621898711928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2779742085120).

1621898711928 is an abundant number, since it is smaller than the sum of its proper divisors (3937585458312).

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

1621898711928 is a wasteful number, since it uses less digits than its factorization.

1621898711928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3470 (or 3454 counting only the distinct ones).

The product of its digits is 6967296, while the sum is 63.

The spelling of 1621898711928 in words is "one trillion, six hundred twenty-one billion, eight hundred ninety-eight million, seven hundred eleven thousand, nine hundred twenty-eight".