155221438 has 16 divisors (see below), whose sum is σ = 239974560. Its totient is φ = 75244896.

The previous prime is 155221399. The next prime is 155221459. The reversal of 155221438 is 834122551.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18103 + ... + 25261.

It is an arithmetic number, because the mean of its divisors is an integer number (14998410).

Almost surely, 2^155221438 is an apocalyptic number.

155221438 is a deficient number, since it is larger than the sum of its proper divisors (84753122).

155221438 is a wasteful number, since it uses less digits than its factorization.

155221438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7491.

The product of its digits is 9600, while the sum is 31.

The square root of 155221438 is about 12458.7895880780. The cubic root of 155221438 is about 537.4242192064.

Adding to 155221438 its reverse (834122551), we get a palindrome (989343989).

The spelling of 155221438 in words is "one hundred fifty-five million, two hundred twenty-one thousand, four hundred thirty-eight".