221256061 has 4 divisors (see below), whose sum is σ = 238275772. Its totient is φ = 204236352.

The previous prime is 221256059. The next prime is 221256073. The reversal of 221256061 is 160652122.

221256061 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 147622500 + 73633561 = 12150^2 + 8581^2 .

It is a cyclic number.

It is not a de Polignac number, because 221256061 - 2¹ = 221256059 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 (221256461) 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, 8509836 + ... + 8509861.

It is an arithmetic number, because the mean of its divisors is an integer number (59568943).

Almost surely, 2^221256061 is an apocalyptic number.

It is an amenable number.

221256061 is a deficient number, since it is larger than the sum of its proper divisors (17019711).

221256061 is a wasteful number, since it uses less digits than its factorization.

221256061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17019710.

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

The square root of 221256061 is about 14874.6785175344. The cubic root of 221256061 is about 604.8277733019.

The spelling of 221256061 in words is "two hundred twenty-one million, two hundred fifty-six thousand, sixty-one".