1621091565120 has 448 divisors, whose sum is σ = 5627892061440. Its totient is φ = 393735831552.

The previous prime is 1621091565109. The next prime is 1621091565133. The reversal of 1621091565120 is 215651901261.

It is a super-2 number, since 2×1621091565120² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 76481244 + ... + 76502436.

Almost surely, 2^{1621091565120} is an apocalyptic number.

1621091565120 is a gapful number since it is divisible by the number (10) 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 1621091565120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2813946030720).

1621091565120 is an abundant number, since it is smaller than the sum of its proper divisors (4006800496320).

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

1621091565120 is a wasteful number, since it uses less digits than its factorization.

1621091565120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21382 (or 21372 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 39.

The spelling of 1621091565120 in words is "one trillion, six hundred twenty-one billion, ninety-one million, five hundred sixty-five thousand, one hundred twenty".