20973909979680 has 384 divisors, whose sum is σ = 79412375863296. Its totient is φ = 4551853363200.

The previous prime is 20973909979657. The next prime is 20973909979697. The reversal of 20973909979680 is 8697990937902.

It is a junction number, because it is equal to n+sod(n) for n = 20973909979596 and 20973909979605.

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, 3620835 + ... + 7420125.

It is an arithmetic number, because the mean of its divisors is an integer number (206803062144).

Almost surely, 2^{20973909979680} is an apocalyptic number.

20973909979680 is a gapful number since it is divisible by the number (20) 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 20973909979680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39706187931648).

20973909979680 is an abundant number, since it is smaller than the sum of its proper divisors (58438465883616).

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

20973909979680 is a wasteful number, since it uses less digits than its factorization.

20973909979680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3799400 (or 3799392 counting only the distinct ones).

The product of its (nonzero) digits is 833299488, while the sum is 78.

The spelling of 20973909979680 in words is "twenty trillion, nine hundred seventy-three billion, nine hundred nine million, nine hundred seventy-nine thousand, six hundred eighty".