155221366 has 4 divisors (see below), whose sum is σ = 232832052. Its totient is φ = 77610682.

The previous prime is 155221361. The next prime is 155221399. The reversal of 155221366 is 663122551.

155221366 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 is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155221361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38805340 + ... + 38805343.

It is an arithmetic number, because the mean of its divisors is an integer number (58208013).

Almost surely, 2^155221366 is an apocalyptic number.

155221366 is a deficient number, since it is larger than the sum of its proper divisors (77610686).

155221366 is an equidigital number, since it uses as much as digits as its factorization.

155221366 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77610685.

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

The square root of 155221366 is about 12458.7866985513. The cubic root of 155221366 is about 537.4241361110.

The spelling of 155221366 in words is "one hundred fifty-five million, two hundred twenty-one thousand, three hundred sixty-six".