221637512657106 has 256 divisors, whose sum is σ = 614369828459520. Its totient is φ = 57668697169920.

The previous prime is 221637512657059. The next prime is 221637512657149. The reversal of 221637512657106 is 601756215736122.

It is a happy number.

221637512657106 is a `hidden beast` number, since 2 + 2 + 1 + 6 + 375 + 1 + 265 + 7 + 1 + 0 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 150367176 + ... + 151833996.

It is an arithmetic number, because the mean of its divisors is an integer number (2399882142420).

Almost surely, 2^{221637512657106} is an apocalyptic number.

221637512657106 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 221637512657106, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (307184914229760).

221637512657106 is an abundant number, since it is smaller than the sum of its proper divisors (392732315802414).

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

221637512657106 is a wasteful number, since it uses less digits than its factorization.

221637512657106 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1467266 (or 1467260 counting only the distinct ones).

The product of its (nonzero) digits is 6350400, while the sum is 54.

The spelling of 221637512657106 in words is "two hundred twenty-one trillion, six hundred thirty-seven billion, five hundred twelve million, six hundred fifty-seven thousand, one hundred six".