221805208111680 has 1792 divisors, whose sum is σ = 885731438592000. Its totient is φ = 51982345175040.

The previous prime is 221805208111651. The next prime is 221805208111783. The reversal of 221805208111680 is 86111802508122.

221805208111680 is a `hidden beast` number, since 2 + 2 + 1 + 8 + 0 + 520 + 8 + 1 + 116 + 8 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 16250649496 + ... + 16250663144.

It is an arithmetic number, because the mean of its divisors is an integer number (494269776000).

Almost surely, 2^{221805208111680} is an apocalyptic number.

221805208111680 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 221805208111680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (442865719296000).

221805208111680 is an abundant number, since it is smaller than the sum of its proper divisors (663926230480320).

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

221805208111680 is a wasteful number, since it uses less digits than its factorization.

221805208111680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13849 (or 13833 counting only the distinct ones).

The product of its (nonzero) digits is 122880, while the sum is 45.

The spelling of 221805208111680 in words is "two hundred twenty-one trillion, eight hundred five billion, two hundred eight million, one hundred eleven thousand, six hundred eighty".