221536765 has 8 divisors (see below), whose sum is σ = 265940568. Its totient is φ = 177165120.

The previous prime is 221536729. The next prime is 221536801. The reversal of 221536765 is 567635122.

It is an interprime number because it is at equal distance from previous prime (221536729) and next prime (221536801).

It can be written as a sum of positive squares in 4 ways, for example, as 91508356 + 130028409 = 9566^2 + 11403^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 221536765 - 2¹¹ = 221534717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11395 + ... + 23935.

It is an arithmetic number, because the mean of its divisors is an integer number (33242571).

Almost surely, 2^221536765 is an apocalyptic number.

It is an amenable number.

221536765 is a deficient number, since it is larger than the sum of its proper divisors (44403803).

221536765 is a wasteful number, since it uses less digits than its factorization.

221536765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16079.

The product of its digits is 75600, while the sum is 37.

The square root of 221536765 is about 14884.1111592194. Note that the first 4 decimals coincide. The cubic root of 221536765 is about 605.0834436280.

The spelling of 221536765 in words is "two hundred twenty-one million, five hundred thirty-six thousand, seven hundred sixty-five".