221506026 has 64 divisors (see below), whose sum is σ = 521579520. Its totient is φ = 61395840.

The previous prime is 221505989. The next prime is 221506049. The reversal of 221506026 is 620605122.

It is a junction number, because it is equal to n+sod(n) for n = 221505987 and 221506005.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 528445 + ... + 528863.

It is an arithmetic number, because the mean of its divisors is an integer number (8149680).

Almost surely, 2^221506026 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221506026, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (260789760).

221506026 is an abundant number, since it is smaller than the sum of its proper divisors (300073494).

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

221506026 is a wasteful number, since it uses less digits than its factorization.

221506026 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 779.

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 221506026 is about 14883.0785121896. The cubic root of 221506026 is about 605.0554565198.

The spelling of 221506026 in words is "two hundred twenty-one million, five hundred six thousand, twenty-six".