136556221 has 4 divisors (see below), whose sum is σ = 142493472. Its totient is φ = 130618972.

The previous prime is 136556219. The next prime is 136556227. The reversal of 136556221 is 122655631.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 136556221 - 2¹ = 136556219 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 (136556227) 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, 2968591 + ... + 2968636.

It is an arithmetic number, because the mean of its divisors is an integer number (35623368).

Almost surely, 2^136556221 is an apocalyptic number.

It is an amenable number.

136556221 is a deficient number, since it is larger than the sum of its proper divisors (5937251).

136556221 is an equidigital number, since it uses as much as digits as its factorization.

136556221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5937250.

The product of its digits is 10800, while the sum is 31.

The square root of 136556221 is about 11685.7272345370. The cubic root of 136556221 is about 514.9564433581.

The spelling of 136556221 in words is "one hundred thirty-six million, five hundred fifty-six thousand, two hundred twenty-one".