20961616221000 has 1536 divisors, whose sum is σ = 93927459225600. Its totient is φ = 4092328396800.

The previous prime is 20961616220959. The next prime is 20961616221053. The reversal of 20961616221000 is 12261616902.

20961616221000 is a `hidden beast` number, since 2 + 0 + 9 + 6 + 1 + 616 + 22 + 10 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 669107337 + ... + 669138663.

It is an arithmetic number, because the mean of its divisors is an integer number (61150689600).

Almost surely, 2^{20961616221000} is an apocalyptic number.

20961616221000 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 20961616221000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46963729612800).

20961616221000 is an abundant number, since it is smaller than the sum of its proper divisors (72965843004600).

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

20961616221000 is a wasteful number, since it uses less digits than its factorization.

20961616221000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31436 (or 31419 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

Adding to 20961616221000 its reverse (12261616902), we get a palindrome (20973877837902).

The spelling of 20961616221000 in words is "twenty trillion, nine hundred sixty-one billion, six hundred sixteen million, two hundred twenty-one thousand".