155645221 has 8 divisors (see below), whose sum is σ = 160562144. Its totient is φ = 150804720.

The previous prime is 155645219. The next prime is 155645227. The reversal of 155645221 is 122546551.

155645221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 155645221 - 2¹ = 155645219 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 (155645227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14955 + ... + 23128.

It is an arithmetic number, because the mean of its divisors is an integer number (20070268).

Almost surely, 2^155645221 is an apocalyptic number.

It is an amenable number.

155645221 is a deficient number, since it is larger than the sum of its proper divisors (4916923).

155645221 is an equidigital number, since it uses as much as digits as its factorization.

155645221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38211.

The product of its digits is 12000, while the sum is 31.

The square root of 155645221 is about 12475.7853860989. The cubic root of 155645221 is about 537.9128636812.

The spelling of 155645221 in words is "one hundred fifty-five million, six hundred forty-five thousand, two hundred twenty-one".