221266501 has 4 divisors (see below), whose sum is σ = 221405292. Its totient is φ = 221127712.

The previous prime is 221266489. The next prime is 221266517. The reversal of 221266501 is 105662122.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 135722500 + 85544001 = 11650^2 + 9249^2 .

It is a cyclic number.

It is not a de Polignac number, because 221266501 - 2¹³ = 221258309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221266531) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66976 + ... + 70201.

It is an arithmetic number, because the mean of its divisors is an integer number (55351323).

Almost surely, 2^221266501 is an apocalyptic number.

It is an amenable number.

221266501 is a deficient number, since it is larger than the sum of its proper divisors (138791).

221266501 is a wasteful number, since it uses less digits than its factorization.

221266501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138790.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 221266501 is about 14875.0294453490. The cubic root of 221266501 is about 604.8372861150.

The spelling of 221266501 in words is "two hundred twenty-one million, two hundred sixty-six thousand, five hundred one".