221981618396376 has 128 divisors (see below), whose sum is σ = 625918876262400. Its totient is φ = 72877833578880.

The previous prime is 221981618396359. The next prime is 221981618396407. The reversal of 221981618396376 is 673693816189122.

221981618396376 is a `hidden beast` number, since 2 + 2 + 1 + 9 + 8 + 161 + 8 + 3 + 96 + 376 = 666.

221981618396376 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 89530926 + ... + 91976898.

It is an arithmetic number, because the mean of its divisors is an integer number (4889991220800).

Almost surely, 2^{221981618396376} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221981618396376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (312959438131200).

221981618396376 is an abundant number, since it is smaller than the sum of its proper divisors (403937257866024).

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

221981618396376 is a wasteful number, since it uses less digits than its factorization.

221981618396376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2452326 (or 2452316 counting only the distinct ones).

The product of its digits is 282175488, while the sum is 72.

The spelling of 221981618396376 in words is "two hundred twenty-one trillion, nine hundred eighty-one billion, six hundred eighteen million, three hundred ninety-six thousand, three hundred seventy-six".