155221504 has 40 divisors (see below), whose sum is σ = 312276888. Its totient is φ = 77076480.

The previous prime is 155221487. The next prime is 155221511. The reversal of 155221504 is 405122551.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 79419 + ... + 81349.

Almost surely, 2^155221504 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 155221504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (156138444).

155221504 is an abundant number, since it is smaller than the sum of its proper divisors (157055384).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

155221504 is an equidigital number, since it uses as much as digits as its factorization.

155221504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2106 (or 2090 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 25.

The square root of 155221504 is about 12458.7922368101. The cubic root of 155221504 is about 537.4242953771.

The spelling of 155221504 in words is "one hundred fifty-five million, two hundred twenty-one thousand, five hundred four".